delete all characters from char to EOL

- more like GNU readline or emacs - can delete entire line with
  ctrl-A ctrl-K

system/cle/cle.c

@@ -1076,7 +1076,7 @@ static int cle_editloop(FAR struct cle_s *priv)
 
         case KEY_DELEOL:  /* Delete to the end of the line */
           {
-            priv->nchars = (priv->nchars > 0 ? priv->curpos + 1 : 0);
+            priv->nchars = (priv->nchars > 0 ? priv->curpos : 0);
           }
           break;