scatterlist: reorder compound boolean expression

Test the cheaper boolean expression with no side effects first.

Link: http://lkml.kernel.org/r/1486040150-14109-2-git-send-email-gilad@benyossef.com


Signed-off-by: Gilad Ben-Yossef <gilad@benyossef.com>
Cc: Jens Axboe <axboe@kernel.dk>
Cc: <ofir.drang@arm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>