test(template) simplify _test_template.c

Originally added here https://github.com/lvgl/lvgl/commit/727808904069ada481f72b0b2c4466ea224fc067
but lost somehow

tests/src/test_cases/_test_template.c

@@ -3,11 +3,6 @@
 
 #include "unity/unity.h"
 
-void setUp(void);
-void tearDown(void);
-
-void test_func_1(void);
-
 void setUp(void)
 {
     /* Function run before every test */
@@ -20,7 +15,7 @@ void tearDown(void)
 
 void test_func_1(void)
 {
-  TEST_ASSERT_EQUAL(actual, expected);
+    TEST_FAIL();
 }
 
 #endif