Fix memory leak (cid #1049518)

lib/vlm.c

@@ -263,11 +263,16 @@ static char* recurse_answer( vlm_message_t *p_answer, const char* psz_delim,
              * inside a list), create a property of its name as if it
              * had a name value node
              */
+            free( psz_nametag );
             if( i_list )
             {
                 i_success = asprintf( &psz_nametag, "\"name\": \"%s\",%s",
                               aw_child->psz_name, psz_childdelim );
-                if( i_success == -1 ) break;
+                if( i_success == -1 )
+                {
+                    psz_nametag = NULL;
+                    break;
+                }
             }
             else
             {