[clang-tidy] use override instead of virtual

Found with modernize-use-override

Signed-off-by: Rosen Penev <rosenp@gmail.com>

test/visit_archive.cxx

@@ -54,7 +54,7 @@ public:
 
 class MyArchiveVisitor final : public ArchiveVisitor {
 public:
-	virtual void VisitArchiveEntry(const char *path_utf8) override {
+	void VisitArchiveEntry(const char *path_utf8) override {
 		printf("%s\n", path_utf8);
 	}
 };