devicemapper: retry remove even for subLVs

With older systems and udevs we don't have control over scanning of lvm2
internal devices - so far we set retry-removal only for top-level LVs,
but in occasional cases udev can be 'fast enough' to open device for
scanning and prevent removal of such device from DM table.

So to combat this case - try to pass 'retry' flag also for removal of
internal device so see how many races can go away with this simple
patch.

Note: patch is applied only to internal version of libdm so the external
API remains working in the old way for now.

device_mapper/libdm-deptree.c

@@ -1792,7 +1792,7 @@ static int _dm_tree_deactivate_children(struct dm_tree_node *dnode,
 
 		if (!_deactivate_node(name, info.major, info.minor,
 				      &child->dtree->cookie, child->udev_flags,
-				      (level == 0) ? child->dtree->retry_remove : 0)) {
+				      child->dtree->retry_remove)) {
 			log_error("Unable to deactivate %s (" FMTu32 ":"
 				  FMTu32 ").", name, info.major, info.minor);
 			r = 0;