x86, um: Correct syscall table type attributes breaking gcc 4.8

The latest GCC 4.8 does some more checking on type attributes that
break the build for ARCH=um -> fill them in.  Specifically, the
"asmlinkage" attributes is now tested for consistency.

Signed-off-by: Martin Pelikan <pelikan@storkhole.cz>
Link: http://lkml.kernel.org/r/1339269731-10772-1-git-send-email-pelikan@storkhole.cz
Acked-by: Richard Weinberger <richard@nod.at>
Signed-off-by: H. Peter Anvin <hpa@zytor.com>

arch/x86/um/sys_call_table_32.c

@@ -39,9 +39,9 @@
 #undef __SYSCALL_I386
 #define __SYSCALL_I386(nr, sym, compat) [ nr ] = sym,
 
-typedef void (*sys_call_ptr_t)(void);
+typedef asmlinkage void (*sys_call_ptr_t)(void);
 
-extern void sys_ni_syscall(void);
+extern asmlinkage void sys_ni_syscall(void);
 
 const sys_call_ptr_t sys_call_table[] __cacheline_aligned = {
 	/*