kconfig: lxdialog is now sparse clean

Replacing a gcc idiom with malloc and deleting an unused global
variable made lxdialog sparse clean.
Signed-off-by: Sam Ravnborg <sam@ravnborg.org>

scripts/lxdialog/menubox.c

@@ -67,7 +67,7 @@ static void print_item(WINDOW * win, const char *item, int choice,
 		       int selected, int hotkey)
 {
 	int j;
-	char menu_item[menu_width + 1];
+	char *menu_item = malloc(menu_width + 1);
 
 	strncpy(menu_item, item, menu_width);
 	menu_item[menu_width] = 0;
@@ -95,6 +95,7 @@ static void print_item(WINDOW * win, const char *item, int choice,
 		wmove(win, choice, item_x + 1);
 		wrefresh(win);
 	}
+	free(menu_item);
 }
 
 /*

scripts/lxdialog/util.c

@@ -26,8 +26,6 @@ bool use_colors = 1;
 
 const char *backtitle = NULL;
 
-const char *dialog_result;
-
 /*
  * Attribute values, default is for mono display
  */