md: use sector_t in bitmap_get_counter

bitmap_get_counter returns the number of sectors covered
by the counter in a pass-by-reference variable.
In some cases this can be very large, so make it a sector_t
for safety.

Signed-off-by: NeilBrown <neilb@suse.de>

diff --git a/drivers/md/raid1.c b/drivers/md/raid1.c
index 378a258..a4b85a9 100644
--- a/drivers/md/raid1.c
+++ b/drivers/md/raid1.c
@@ -1245,7 +1245,7 @@
 			break;
 		}
 	if (!uptodate) {
-		int sync_blocks = 0;
+		sector_t sync_blocks = 0;
 		sector_t s = r1_bio->sector;
 		long sectors_to_go = r1_bio->sectors;
 		/* make sure these bits doesn't get cleared. */
@@ -1705,7 +1705,7 @@
 	int i;
 	int wonly = -1;
 	int write_targets = 0, read_targets = 0;
-	int sync_blocks;
+	sector_t sync_blocks;
 	int still_degraded = 0;
 
 	if (!conf->r1buf_pool)