test_gengrid.c: Fixed Item_Data array size for prevent buffer overflow.

Summary:
Item_Data size set as 144 before. but test_gengrid_speed function called create_gengrid function with 5000 items.
it makes crash.

@fix

Test Plan:
1. run elementary_test.
2. click Gengrid update Speed.
3. crash.

Reviewers: seoz, Hermet

Reviewed By: Hermet

Differential Revision: https://phab.enlightenment.org/D1834

legacy/elementary/src/bin/test_gengrid.c

@@ -355,7 +355,7 @@ static Evas_Object *
 create_gengrid(Evas_Object *obj, int items)
 {
    Evas_Object *grid = NULL;
-   static Item_Data id[144];
+   static Item_Data id[5000];
    int i, n;
    char buf[PATH_MAX];