Remove syscall module.

This module merely contained FFI declarations, and only enough to
implement memfd_create() and pivot_root() wrapper functions in
nix. Since these declarations are redundant with equivalent FFI
declarations in libc, we'll remove them here. In the future, any
syscall-related wrapper function will be implemented directly and
utilize libc for FFI declarations as we cannot generically expose
a type-safe `syscall()` because of its variadic argument list.

1 files changed, 3 insertions, 2 deletions

diff --git a/src/sys/memfd.rs b/src/sys/memfd.rs
index b9812943..056e9e43 100644
--- a/src/sys/memfd.rs
+++ b/src/sys/memfd.rs
@@ -11,8 +11,9 @@ bitflags!(
 );
 
 pub fn memfd_create(name: &CStr, flags: MemFdCreateFlag) -> Result<RawFd> {
-    use sys::syscall::{syscall, MEMFD_CREATE};
-    let res = unsafe { syscall(MEMFD_CREATE, name.as_ptr(), flags.bits()) };
+    let res = unsafe {
+        libc::syscall(libc::SYS_memfd_create, name.as_ptr(), flags.bits())
+    };
 
     Errno::result(res).map(|r| r as RawFd)
 }