ftp_done: remove dead code

lib/ftp.c

@@ -3250,7 +3250,6 @@ static CURLcode ftp_done(struct connectdata *conn, CURLcode status,
   ssize_t nread;
   int ftpcode;
   CURLcode result = CURLE_OK;
-  bool was_ctl_valid = ftpc->ctl_valid;
   char *path;
   const char *path_to_use = data->state.path;
 
@@ -3274,10 +3273,9 @@ static CURLcode ftp_done(struct connectdata *conn, CURLcode status,
     /* the connection stays alive fine even though this happened */
     /* fall-through */
   case CURLE_OK: /* doesn't affect the control connection's status */
-    if(!premature) {
-      ftpc->ctl_valid = was_ctl_valid;
+    if(!premature)
       break;
-    }
+
     /* until we cope better with prematurely ended requests, let them
      * fallback as if in complete failure */
   default:       /* by default, an error means the control connection is