fix: handle error on rename

main.go

@@ -114,7 +114,10 @@ func normalize(p string, f os.FileInfo, err error) error {
 		if dryrun {
 			fmt.Printf("Would move %s to %s\n", p, newPath)
 		} else {
-			os.Rename(p, newPath)
+			err = os.Rename(p, newPath)
+			if err != nil {
+				return err
+			}
 			fmt.Printf("%s => %s\n", p, newPath)
 		}
 	}