md/raid5: get rid of duplicated call to bio_data_dir()

In raid5::make_request(), once bio_data_dir(@bi) is detected
it never (and couldn't) be changed. Use the result always.
Signed-off-by: Namhyung Kim <namhyung@gmail.com>
Signed-off-by: NeilBrown <neilb@suse.de>

drivers/md/raid5.c

@@ -4014,7 +4014,7 @@ static int make_request(mddev_t *mddev, struct bio * bi)
 				}
 			}
 
-			if (bio_data_dir(bi) == WRITE &&
+			if (rw == WRITE &&
 			    logical_sector >= mddev->suspend_lo &&
 			    logical_sector < mddev->suspend_hi) {
 				release_stripe(sh);
@@ -4032,7 +4032,7 @@ static int make_request(mddev_t *mddev, struct bio * bi)
 			}
 
 			if (test_bit(STRIPE_EXPANDING, &sh->state) ||
-			    !add_stripe_bio(sh, bi, dd_idx, (bi->bi_rw&RW_MASK))) {
+			    !add_stripe_bio(sh, bi, dd_idx, rw)) {
 				/* Stripe is busy expanding or
 				 * add failed due to overlap.  Flush everything
 				 * and wait a while