Fix clippy warnings on nightly

Clippy is now smarter about detecting unnecessary casts and
useless conversions, which means we need to be more explicit
about when the conversions are needed for a subset of platforms.

Required changes found by repeatedly running the following command
against a list of the supported platforms.

`xargs -t -I {} sh -c "cargo clippy -Zbuild-std --target {} --all-targets -- -D warnings || exit 255"`

I removed the casts it complained about, and then restored them
with an `#[allow]` if a later target needed the cast.

1 files changed, 17 insertions, 15 deletions

diff --git a/src/sys/socket/addr.rs b/src/sys/socket/addr.rs
index 6b2ba21c..07d68e1f 100644
--- a/src/sys/socket/addr.rs
+++ b/src/sys/socket/addr.rs
@@ -935,7 +935,7 @@ impl SockaddrLike for UnixAddr {
                 return None;
             }
         }
-        if (*addr).sa_family as i32 != libc::AF_UNIX as i32 {
+        if (*addr).sa_family as i32 != libc::AF_UNIX {
             return None;
         }
         let mut su: libc::sockaddr_un = mem::zeroed();
@@ -1192,7 +1192,7 @@ impl SockaddrLike for SockaddrIn {
                 return None;
             }
         }
-        if (*addr).sa_family as i32 != libc::AF_INET as i32 {
+        if (*addr).sa_family as i32 != libc::AF_INET {
             return None;
         }
         Some(Self(ptr::read_unaligned(addr as *const _)))
@@ -1298,7 +1298,7 @@ impl SockaddrLike for SockaddrIn6 {
                 return None;
             }
         }
-        if (*addr).sa_family as i32 != libc::AF_INET6 as i32 {
+        if (*addr).sa_family as i32 != libc::AF_INET6 {
             return None;
         }
         Some(Self(ptr::read_unaligned(addr as *const _)))
@@ -2101,7 +2101,7 @@ pub mod netlink {
                     return None;
                 }
             }
-            if (*addr).sa_family as i32 != libc::AF_NETLINK as i32 {
+            if (*addr).sa_family as i32 != libc::AF_NETLINK {
                 return None;
             }
             Some(Self(ptr::read_unaligned(addr as *const _)))
@@ -2145,7 +2145,7 @@ pub mod alg {
                     return None;
                 }
             }
-            if (*addr).sa_family as i32 != libc::AF_ALG as i32 {
+            if (*addr).sa_family as i32 != libc::AF_ALG {
                 return None;
             }
             Some(Self(ptr::read_unaligned(addr as *const _)))
@@ -2259,7 +2259,7 @@ pub mod sys_control {
                     return None;
                 }
             }
-            if (*addr).sa_family as i32 != libc::AF_SYSTEM as i32 {
+            if (*addr).sa_family as i32 != libc::AF_SYSTEM {
                 return None;
             }
             Some(Self(ptr::read_unaligned(addr as *const _)))
@@ -2366,12 +2366,12 @@ mod datalink {
         // Returns an Option just for cross-platform compatibility
         pub fn addr(&self) -> Option<[u8; 6]> {
             Some([
-                self.0.sll_addr[0] as u8,
-                self.0.sll_addr[1] as u8,
-                self.0.sll_addr[2] as u8,
-                self.0.sll_addr[3] as u8,
-                self.0.sll_addr[4] as u8,
-                self.0.sll_addr[5] as u8,
+                self.0.sll_addr[0],
+                self.0.sll_addr[1],
+                self.0.sll_addr[2],
+                self.0.sll_addr[3],
+                self.0.sll_addr[4],
+                self.0.sll_addr[5],
             ])
         }
     }
@@ -2402,7 +2402,7 @@ mod datalink {
                     return None;
                 }
             }
-            if (*addr).sa_family as i32 != libc::AF_PACKET as i32 {
+            if (*addr).sa_family as i32 != libc::AF_PACKET {
                 return None;
             }
             Some(Self(ptr::read_unaligned(addr as *const _)))
@@ -2477,6 +2477,8 @@ mod datalink {
         }
 
         /// Physical-layer address (MAC)
+        // The cast is not unnecessary on all platforms.
+        #[allow(clippy::unnecessary_cast)]
         pub fn addr(&self) -> Option<[u8; 6]> {
             let nlen = self.nlen();
             let data = self.0.sdl_data;
@@ -2522,7 +2524,7 @@ mod datalink {
                     return None;
                 }
             }
-            if (*addr).sa_family as i32 != libc::AF_LINK as i32 {
+            if (*addr).sa_family as i32 != libc::AF_LINK {
                 return None;
             }
             Some(Self(ptr::read_unaligned(addr as *const _)))
@@ -2566,7 +2568,7 @@ pub mod vsock {
                     return None;
                 }
             }
-            if (*addr).sa_family as i32 != libc::AF_VSOCK as i32 {
+            if (*addr).sa_family as i32 != libc::AF_VSOCK {
                 return None;
             }
             Some(Self(ptr::read_unaligned(addr as *const _)))