Fix a compilater warning on Windows 64-bit
diff --git a/Python/formatter_unicode.c b/Python/formatter_unicode.c
index 548b49a..bb173d9 100644
--- a/Python/formatter_unicode.c
+++ b/Python/formatter_unicode.c
@@ -315,7 +315,7 @@
 
 /* Do the padding, and return a pointer to where the caller-supplied
    content goes. */
-static Py_ssize_t
+static int
 fill_padding(_PyUnicodeWriter *writer,
              Py_ssize_t nchars,
              Py_UCS4 fill_char, Py_ssize_t n_lpadding,