Solved a bunch of -Wall errors on modern

src/field_message_box.c

@@ -97,8 +97,7 @@ bool8 ShowFieldAutoScrollMessage(const u8 *str)
     return TRUE;
 }
 
-// Unused
-static bool8 ForceShowFieldAutoScrollMessage(const u8 *str)
+static bool8 UNUSED ForceShowFieldAutoScrollMessage(const u8 *str)
 {
     sFieldMessageBoxMode = FIELD_MESSAGE_BOX_AUTO_SCROLL;
     ExpandStringAndStartDrawFieldMessage(str, TRUE);
@@ -148,8 +147,7 @@ bool8 IsFieldMessageBoxHidden(void)
     return FALSE;
 }
 
-// Unused
-static void ReplaceFieldMessageWithFrame(void)
+static void UNUSED ReplaceFieldMessageWithFrame(void)
 {
     DestroyTask_DrawFieldMessage();
     DrawStdWindowFrame(0, TRUE);