[gimp/gimp-2-10] plug-ins: fix incorrect cherry-picking of previous commit.

[Jacob Boerema <jboerema src gnome org>]

commit 557a19469a968066ccb0496d42ac12aca43fd6d3
Author: Jacob Boerema <jgboerema gmail com>
Date:   Wed May 19 22:29:37 2021 -0400

    plug-ins: fix incorrect cherry-picking of previous commit.

 plug-ins/common/file-gif-save.c | 6 ++----
 1 file changed, 2 insertions(+), 4 deletions(-)
---
diff --git a/plug-ins/common/file-gif-save.c b/plug-ins/common/file-gif-save.c
index 43d7dd92d5..ddb555d7bc 100644
--- a/plug-ins/common/file-gif-save.c
+++ b/plug-ins/common/file-gif-save.c
@@ -799,11 +799,9 @@ save_image (GFile   *file,
       if (drawable_type == GIMP_GRAY_IMAGE ||
           drawable_type == GIMP_INDEXED_IMAGE)
         {
-          for (list = layers, i = nlayers - 1;
-              list && i >= 0;
-              list = g_list_next (list), i--, cur_progress = (nlayers - i) * rows)
+          for (i = nlayers - 1; i >= 0; i--)
             {
-              GimpImageType dr_type = gimp_drawable_type (drawable);
+              GimpImageType dr_type = gimp_drawable_type (layers[i]);
 
               if (dr_type == GIMP_GRAYA_IMAGE ||
                   dr_type == GIMP_INDEXEDA_IMAGE)