Renamed TGA Unit Test def

Makefile

@@ -371,7 +371,7 @@ endif
 
 TGA.test:
 	mkdir -p $(BUILD_TEST_DIR)
-	$(CC) $(TEST_FLAGS) -D__TEST_ \
+	$(CC) $(TEST_FLAGS) -DUNIT_TEST_TGA \
 		src/mtk_tga.cpp -o $(BUILD_TEST_DIR)/TGA.test
 
 #################################################################

src/mtk_tga.cpp

@@ -490,7 +490,7 @@ int mtk_image__tga_save_filename(unsigned char *image,
 }
 
 
-#ifdef __TEST_
+#ifdef UNIT_TEST_TGA
 int main(int argc, char *argv[])
 {
   FILE *f;