[gimp] plug-ins: fix computation of padding in fread_unicode_string.

[Jacob Boerema <jboerema src gnome org>]

commit eb78aa994e05a9fdee9d5c962d0350c2388e1936
Author: Jacob Boerema <jgboerema gmail com>
Date:   Wed May 12 17:24:58 2021 -0400

    plug-ins: fix computation of padding in fread_unicode_string.

 plug-ins/file-psd/psd-util.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)
---
diff --git a/plug-ins/file-psd/psd-util.c b/plug-ins/file-psd/psd-util.c
index 9ea1260f41..533a9b0557 100644
--- a/plug-ins/file-psd/psd-util.c
+++ b/plug-ins/file-psd/psd-util.c
@@ -423,7 +423,7 @@ fread_unicode_string (gint32        *bytes_read,
 
   if (mod_len > 0)
     {
-      padded_len = len + 1;
+      padded_len = *bytes_read;
       while (padded_len % mod_len != 0)
         {
           if (! psd_seek (input, 1, G_SEEK_CUR, error))