md: use set_bit/clear_bit instead of shift/mask for bi_flags changes.

Using {set,clear}_bit is more consistent than shifting and masking.

No functional change.
Signed-off-by: NeilBrown <neilb@suse.de>

drivers/md/raid1.c

@@ -2722,7 +2722,7 @@ static sector_t sync_request(struct mddev *mddev, sector_t sector_nr, int *skipp
 						/* remove last page from this bio */
 						bio->bi_vcnt--;
 						bio->bi_iter.bi_size -= len;
-						bio->bi_flags &= ~(1<< BIO_SEG_VALID);
+						__clear_bit(BIO_SEG_VALID, &bio->bi_flags);
 					}
 					goto bio_full;
 				}

drivers/md/raid10.c

@@ -3388,7 +3388,7 @@ static sector_t sync_request(struct mddev *mddev, sector_t sector_nr,
 				/* remove last page from this bio */
 				bio2->bi_vcnt--;
 				bio2->bi_iter.bi_size -= len;
-				bio2->bi_flags &= ~(1<< BIO_SEG_VALID);
+				__clear_bit(BIO_SEG_VALID, &bio2->bi_flags);
 			}
 			goto bio_full;
 		}
@@ -4416,7 +4416,7 @@ static sector_t reshape_request(struct mddev *mddev, sector_t sector_nr,
 	read_bio->bi_end_io = end_sync_read;
 	read_bio->bi_rw = READ;
 	read_bio->bi_flags &= (~0UL << BIO_RESET_BITS);
-	read_bio->bi_flags |= 1 << BIO_UPTODATE;
+	__set_bit(BIO_UPTODATE, &read_bio->bi_flags);
 	read_bio->bi_vcnt = 0;
 	read_bio->bi_iter.bi_size = 0;
 	r10_bio->master_bio = read_bio;
@@ -4473,7 +4473,7 @@ static sector_t reshape_request(struct mddev *mddev, sector_t sector_nr,
 				/* Remove last page from this bio */
 				bio2->bi_vcnt--;
 				bio2->bi_iter.bi_size -= len;
-				bio2->bi_flags &= ~(1<<BIO_SEG_VALID);
+				__clear_bit(BIO_SEG_VALID, &bio2->bi_flags);
 			}
 			goto bio_full;
 		}

drivers/md/raid5.c

@@ -4301,7 +4301,7 @@ static int chunk_aligned_read(struct mddev *mddev, struct bio * raid_bio)
 		rcu_read_unlock();
 		raid_bio->bi_next = (void*)rdev;
 		align_bi->bi_bdev =  rdev->bdev;
-		align_bi->bi_flags &= ~(1 << BIO_SEG_VALID);
+		__clear_bit(BIO_SEG_VALID, &align_bi->bi_flags);
 
 		if (!bio_fits_rdev(align_bi) ||
 		    is_badblock(rdev, align_bi->bi_iter.bi_sector,