uapi: Use __kernel_long_t in struct mq_attr

Both x32 and x86-64 use the same struct mq_attr for system calls.  But
x32 long is 32-bit. This patch replaces long with __kernel_long_t in
struct mq_attr.

Signed-off-by: H.J. Lu <hjl.tools@gmail.com>
Link: http://lkml.kernel.org/r/1388182464-28428-9-git-send-email-hjl.tools@gmail.com
Signed-off-by: H. Peter Anvin <hpa@zytor.com>

diff --cc include/uapi/linux/mqueue.h
Simple merge