Normalize expected path for chdir tests

The expected path comes from a simple string concatenation in shell, but
`os.Getwd` appears to have the normalized working directory, so this can
fail if any parent directory is a symlink.

tests/testing/chdir/chdir.go

@@ -14,6 +14,10 @@ argument.
 */
 func main() {
 	expectDir := os.Getenv("EXPECT_DIR")
+	expectDir, err := filepath.EvalSymlinks(expectDir)
+	if err != nil {
+		log.Fatal(err)
+	}
 	cwd, err := os.Getwd()
 	if err != nil {
 		log.Fatal(err)