Rename is_internal to always_set_to_false

Update #2825.

testsuites/smptests/smpfatal03/init.c

@@ -67,13 +67,13 @@ static void Init( rtems_task_argument arg )
 
 static void fatal_extension(
   rtems_fatal_source source,
-  bool is_internal,
+  bool always_set_to_false,
   rtems_fatal_code code
 )
 {
   if (
     source == INTERNAL_ERROR_CORE
-      && !is_internal
+      && !always_set_to_false
       && code == INTERNAL_ERROR_THREAD_QUEUE_ENQUEUE_STICKY_FROM_BAD_STATE
   ) {
     TEST_END();