async: fix small typo when printing fixup errors

Fix Coverity #199935

(cherry picked from commit cae397c)

action.c

@@ -2013,7 +2013,7 @@ int do_action(struct action* a, struct sip_msg* msg)
 
 				if (free_cmd_fixups(acmd->params, aitem->elem, cmdp) < 0) {
 					LM_ERR("Failed to free fixups for command <%s>\n",
-						cmd->name);
+						acmd->name);
 					break;
 				}
 			}