use __val in __get_unaligned

Use "__val" rather than "val" in the __get_unaligned macro in
asm-generic/unaligned.h.  This way gcc wont warn if you happen to also name
something in the same scope "val".

Signed-off-by: Mike Frysinger <vapier@gentoo.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>