Revert "test(mem) add test for #3324"

This reverts commit 97006647d8.

tests/src/test_cases/test_mem.c

@@ -1,25 +0,0 @@
-#if LV_BUILD_TEST
-#include "../lvgl.h"
-
-#include "unity/unity.h"
-
-void setUp(void)
-{
-    /* Function run before every test */
-}
-
-void tearDown(void)
-{
-    /* Function run after every test */
-}
-
-/* #3324 */
-void test_mem_buf_realloc(void)
-{
-#if LV_MEM_CUSTOM == 0
-    void * buf = lv_mem_buf_get(LV_MEM_SIZE + 16384);
-    TEST_ASSERT_NULL(buf);
-#endif
-}
-
-#endif