chore: fix warning

examples/widgets/keyboard/lv_example_keyboard_2.c

@@ -1,22 +1,6 @@
 #include "../../lv_examples.h"
 #if LV_USE_KEYBOARD && LV_BUILD_EXAMPLES
 
-static void ta_event_cb(lv_event_t * e)
-{
-    lv_event_code_t code = lv_event_get_code(e);
-    lv_obj_t * ta = lv_event_get_target(e);
-    lv_obj_t * kb = lv_event_get_user_data(e);
-    if(code == LV_EVENT_FOCUSED) {
-        lv_keyboard_set_textarea(kb, ta);
-        lv_obj_clear_flag(kb, LV_OBJ_FLAG_HIDDEN);
-    }
-
-    if(code == LV_EVENT_DEFOCUSED) {
-        lv_keyboard_set_textarea(kb, NULL);
-        lv_obj_add_flag(kb, LV_OBJ_FLAG_HIDDEN);
-    }
-}
-
 void lv_example_keyboard_2(void)
 {
     /*Create an AZERTY keyboard map*/