skiplist: Fix previous skiplist fix

The last fix to skiplist never ran the code that patched up the level
list as it updated the current level before runnign the loop.

This now works.

Merges: #333
Reviewed-by: Jan Pokorný <jpokorny@redhat.com>

lib/skiplist.c

@@ -505,10 +505,10 @@ skiplist_rm(struct qb_map *map, const char *key)
 	   (header) preceding @found_node, which can be distinguished with
 	   NULL being used as a key (second allowing condition below). */
 	if (found_node->refcount > 1 || cur_node->key == NULL) {
-		found_node->level = SKIPLIST_LEVEL_MIN - 1;  /* no "forward" drop */
 		for (level = SKIPLIST_LEVEL_MIN; level <= found_node->level; level++) {
 			found_node->forward[level] = cur_node->forward[level];
 		}
+		found_node->level = SKIPLIST_LEVEL_MIN - 1;  /* no "forward" drop */
 		free(cur_node->forward);
 		cur_node->forward = found_node->forward;
 	}