use return NULL; it's just as correct

Objects/unicodeobject.c

@@ -769,7 +769,7 @@ PyUnicode_FromFormatV(const char *format, va_list vargs)
                 "PyUnicode_FromFormatV() expects an ASCII-encoded format "
                 "string, got a non-ASCII byte: 0x%02x",
                 (unsigned char)*f);
-             goto fail;
+             return NULL;
          }
     }
     /* step 2: allocate memory for the results of