kfifo: add parenthesis for macro parameter reference

Some macro parameter references inside typeof() operator are not enclosed
with parenthesis.  It should be safer to add them.

Signed-off-by: Huang Ying <ying.huang@intel.com>
Acked-by: Stefani Seibold <stefani@seibold.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

diff --cc include/linux/kfifo.h
Simple merge