Index: b/usr/src/uts/common/fs/zfs/vdev.c
===================================================================
--- a/usr/src/uts/common/fs/zfs/vdev.c	2014-03-10 12:36:51.695959906 +0400
+++ b/usr/src/uts/common/fs/zfs/vdev.c	2014-03-10 12:37:13.482272874 +0400
@@ -1091,7 +1091,7 @@
 
 	for (int c = 0; c < children; c++)
 		VERIFY(taskq_dispatch(tq, vdev_open_child, vd->vdev_child[c],
-		    TQ_SLEEP) != NULL);
+		    TQ_SLEEP) != 0);
 
 	taskq_destroy(tq);
 }