Don't use win32-only macro in test code

tests-clar/status/worktree.c

@@ -868,7 +868,7 @@ void test_status_worktree__sorting_by_case(void)
 
 void test_status_worktree__long_filenames(void)
 {
-	char path[GIT_WIN_PATH_UTF8];
+	char path[260*4+1];
 	const char *expected_paths[] = {path};
 	const unsigned int expected_statuses[] = {GIT_STATUS_WT_NEW};