Meta: Add a script check the presence of "#pragma once" in header files

.. and make travis run it.

I renamed check-license-headers.sh to check-style.sh and expanded it so
that it now also checks for the presence of "#pragma once" in .h files.

It also checks the presence of a (single) blank line above and below the
"#pragma once" line.

I also added "#pragma once" to all the files that need it: even the ones
we are not check.
I also added/removed blank lines in order to make the script not fail.

I also ran clang-format on the files I modified.

7 files changed, 11 insertions, 3 deletions

diff --git a/Kernel/Devices/PATAChannel.h b/Kernel/Devices/PATAChannel.h
index c7ac026edd..09eed4216c 100644
--- a/Kernel/Devices/PATAChannel.h
+++ b/Kernel/Devices/PATAChannel.h
@@ -34,17 +34,18 @@
 // More information about the ATA spec for PATA can be found here:
 //      ftp://ftp.seagate.com/acrobat/reference/111-1c.pdf
 //
+
 #pragma once
 
 #include <AK/OwnPtr.h>
 #include <AK/RefPtr.h>
+#include <Kernel/IO.h>
 #include <Kernel/Lock.h>
 #include <Kernel/PCI/Access.h>
 #include <Kernel/PCI/Device.h>
+#include <Kernel/PhysicalAddress.h>
 #include <Kernel/VM/PhysicalPage.h>
 #include <Kernel/WaitQueue.h>
-#include <Kernel/IO.h>
-#include <Kernel/PhysicalAddress.h>
 
 namespace Kernel {
 
diff --git a/Kernel/Devices/PATADiskDevice.h b/Kernel/Devices/PATADiskDevice.h
index 434aa0dfa1..9c0f051e26 100644
--- a/Kernel/Devices/PATADiskDevice.h
+++ b/Kernel/Devices/PATADiskDevice.h
@@ -27,7 +27,7 @@
 //
 // A Disk Device Connected to a PATA Channel
 //
-//
+
 #pragma once
 
 #include <Kernel/Devices/BlockDevice.h>
diff --git a/Kernel/Devices/SerialDevice.h b/Kernel/Devices/SerialDevice.h
index cdfeec109e..a7f5fd4656 100644
--- a/Kernel/Devices/SerialDevice.h
+++ b/Kernel/Devices/SerialDevice.h
@@ -24,6 +24,8 @@
  * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  */
 
+#pragma once
+
 #include <Kernel/Devices/CharacterDevice.h>
 
 namespace Kernel {
diff --git a/Kernel/FileSystem/ext2_types.h b/Kernel/FileSystem/ext2_types.h
index 223d8195e5..1f79227daf 100644
--- a/Kernel/FileSystem/ext2_types.h
+++ b/Kernel/FileSystem/ext2_types.h
@@ -24,6 +24,8 @@
  * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  */
 
+#pragma once
+
 /* 
  * If linux/types.h is already been included, assume it has defined
  * everything we need.  (cross fingers)  Other header files may have 
diff --git a/Kernel/PCI/IOAccess.h b/Kernel/PCI/IOAccess.h
index 57b66da2b6..eb2468c759 100644
--- a/Kernel/PCI/IOAccess.h
+++ b/Kernel/PCI/IOAccess.h
@@ -25,6 +25,7 @@
  */
 
 #pragma once
+
 #include <Kernel/PCI/Access.h>
 
 namespace Kernel {
diff --git a/Kernel/PCI/MMIOAccess.h b/Kernel/PCI/MMIOAccess.h
index 984dcf31d1..d763a9bcfb 100644
--- a/Kernel/PCI/MMIOAccess.h
+++ b/Kernel/PCI/MMIOAccess.h
@@ -25,6 +25,7 @@
  */
 
 #pragma once
+
 #include <AK/HashMap.h>
 #include <AK/OwnPtr.h>
 #include <AK/Types.h>
diff --git a/Kernel/Ptrace.h b/Kernel/Ptrace.h
index c305cf3f89..6145ffa637 100644
--- a/Kernel/Ptrace.h
+++ b/Kernel/Ptrace.h
@@ -25,6 +25,7 @@
  */
 
 #pragma once
+
 #include <Kernel/KResult.h>
 #include <Kernel/Process.h>
 #include <Kernel/Syscall.h>