Add missing terminal newlines

audio_rules.mk

@@ -42,4 +42,4 @@ $(foreach line,$(shell cat $(MID_CFG_PATH) | sed "s/ /__SPACE__/g"),$(call MID_E
 
 # Warn users building without a .cfg - build will fail at link time
 $(MID_ASM_DIR)/%.s: $(MID_SUBDIR)/%.mid
-	$(warning $< does not have an associated entry in midi.cfg! It cannot be built)
+	$(warning $< does not have an associated entry in midi.cfg! It cannot be built)