dm: use bool bitfields in struct dm_target

Use boolean bit fields for flags in struct dm_target.

Signed-off-by: Alasdair G Kergon <agk@redhat.com>
diff --git a/drivers/md/dm-thin.c b/drivers/md/dm-thin.c
index ee5a3fc..0262155 100644
--- a/drivers/md/dm-thin.c
+++ b/drivers/md/dm-thin.c
@@ -2053,7 +2053,7 @@
 		 * stacking of discard limits (this keeps the pool and
 		 * thin devices' discard limits consistent).
 		 */
-		ti->discards_supported = 1;
+		ti->discards_supported = true;
 	}
 	ti->private = pt;
 
@@ -2656,11 +2656,11 @@
 
 	/* In case the pool supports discards, pass them on. */
 	if (tc->pool->pf.discard_enabled) {
-		ti->discards_supported = 1;
+		ti->discards_supported = true;
 		ti->num_discard_requests = 1;
-		ti->discard_zeroes_data_unsupported = 1;
+		ti->discard_zeroes_data_unsupported = true;
 		/* Discard requests must be split on a block boundary */
-		ti->split_discard_requests = 1;
+		ti->split_discard_requests = true;
 	}
 
 	dm_put(pool_md);