Replace unnecessary x86 uses of <sys/linux-syscalls.h> with <asm/unistd.h>.

Change-Id: I9d016ee8e8329cccf244d27c336d9524348af996
diff --git a/libc/arch-x86/bionic/syscall.S b/libc/arch-x86/bionic/syscall.S
index ef816b6..4452da4 100644
--- a/libc/arch-x86/bionic/syscall.S
+++ b/libc/arch-x86/bionic/syscall.S
@@ -10,8 +10,8 @@
  *	%ebp: arg5                -   callee save
  */
 
+#include <asm/unistd.h>
 #include <machine/asm.h>
-#include <sys/linux-syscalls.h>
 
 ENTRY(syscall)
     # Push the callee save registers.