bcachefs: Fix iterator leak in may_delete_deleted_inode()

may_delete_deleted_inode() was returning without exiting a btree
iterator, eventually causing propagate_key_to_snaphot_leaves() to go
into an infinite loop hitting btree_trans_too_many_iters().

Signed-off-by: Kent Overstreet <[e-mail]>

fs/bcachefs/inode.c

···
 		 * unlinked inodes in the snapshot leaves:
 		 */
 		*need_another_pass = true;
-		return 0;
+		goto out;
 	}
 
 	ret = 1;