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>