md/raid5: Change or of some order to improve efficiency.

As the function call is the most expensive of these tests it should be
done later in the chain so that it can be avoided in some cases.
Signed-off-by: NJianpeng Ma <majianpeng@gmail.com>
Signed-off-by: NNeilBrown <neilb@suse.de>

drivers/md/raid5.c

@@ -4672,9 +4672,10 @@ static inline sector_t sync_request(struct mddev *mddev, sector_t sector_nr, int
 		*skipped = 1;
 		return rv;
 	}
-	if (!bitmap_start_sync(mddev->bitmap, sector_nr, &sync_blocks, 1) &&
-	    !test_bit(MD_RECOVERY_REQUESTED, &mddev->recovery) &&
-	    !conf->fullsync && sync_blocks >= STRIPE_SECTORS) {
+	if (!test_bit(MD_RECOVERY_REQUESTED, &mddev->recovery) &&
+	    !conf->fullsync &&
+	    !bitmap_start_sync(mddev->bitmap, sector_nr, &sync_blocks, 1) &&
+	    sync_blocks >= STRIPE_SECTORS) {
 		/* we can skip this block, and probably more */
 		sync_blocks /= STRIPE_SECTORS;
 		*skipped = 1;