Fix test.

format-test.cc

@@ -1434,7 +1434,7 @@ TEST(FormatterTest, Examples) {
   std::string path = "somefile";
   ReportError("File not found: {0}") << path;
 
-#ifdef FMT_USE_INITIALIZER_LIST
+#if FMT_USE_INITIALIZER_LIST
   EXPECT_THROW_MSG(
     Format("The answer is {:d}", "forty-two"), FormatError,
     "unknown format code 'd' for string");