Free resources on remote close

Deallocate resources immediately if client closes connection.

ftpd.c

@@ -1264,6 +1264,8 @@ static err_t ftpd_msgrecv(void *arg, struct tcp_pcb *pcb, struct pbuf *p, err_t
 			free(text);
 		}
 		pbuf_free(p);
+	} else if (err == ERR_OK && p != NULL) {
+	    ftpd_msgclose(pcb, fsm);
 	}
 
 	return ERR_OK;