md: change type of first arg to sync_page_io.

Currently sync_page_io takes a 'bdev'.
Every caller passes 'rdev->bdev'.
We will soon want another field out of the rdev in sync_page_io,
So just pass the rdev instead of the bdev out of it.

Signed-off-by: NeilBrown <neilb@suse.de>
diff --git a/drivers/md/raid1.c b/drivers/md/raid1.c
index 6cb6cae..08c66af 100644
--- a/drivers/md/raid1.c
+++ b/drivers/md/raid1.c
@@ -1382,7 +1382,7 @@
 					 * active, and resync is currently active
 					 */
 					rdev = conf->mirrors[d].rdev;
-					if (sync_page_io(rdev->bdev,
+					if (sync_page_io(rdev,
 							 sect + rdev->data_offset,
 							 s<<9,
 							 bio->bi_io_vec[idx].bv_page,
@@ -1408,7 +1408,7 @@
 						continue;
 					rdev = conf->mirrors[d].rdev;
 					atomic_add(s, &rdev->corrected_errors);
-					if (sync_page_io(rdev->bdev,
+					if (sync_page_io(rdev,
 							 sect + rdev->data_offset,
 							 s<<9,
 							 bio->bi_io_vec[idx].bv_page,
@@ -1423,7 +1423,7 @@
 					if (r1_bio->bios[d]->bi_end_io != end_sync_read)
 						continue;
 					rdev = conf->mirrors[d].rdev;
-					if (sync_page_io(rdev->bdev,
+					if (sync_page_io(rdev,
 							 sect + rdev->data_offset,
 							 s<<9,
 							 bio->bi_io_vec[idx].bv_page,
@@ -1507,7 +1507,7 @@
 			rdev = conf->mirrors[d].rdev;
 			if (rdev &&
 			    test_bit(In_sync, &rdev->flags) &&
-			    sync_page_io(rdev->bdev,
+			    sync_page_io(rdev,
 					 sect + rdev->data_offset,
 					 s<<9,
 					 conf->tmppage, READ))
@@ -1533,7 +1533,7 @@
 			rdev = conf->mirrors[d].rdev;
 			if (rdev &&
 			    test_bit(In_sync, &rdev->flags)) {
-				if (sync_page_io(rdev->bdev,
+				if (sync_page_io(rdev,
 						 sect + rdev->data_offset,
 						 s<<9, conf->tmppage, WRITE)
 				    == 0)
@@ -1550,7 +1550,7 @@
 			rdev = conf->mirrors[d].rdev;
 			if (rdev &&
 			    test_bit(In_sync, &rdev->flags)) {
-				if (sync_page_io(rdev->bdev,
+				if (sync_page_io(rdev,
 						 sect + rdev->data_offset,
 						 s<<9, conf->tmppage, READ)
 				    == 0)