[gimp] plug-ins: fix small memory leak from MR !627.

[Jehan <jehanp src gnome org>]

commit 12c7501552a4cfe649ebbe557ef684272b85e2c1
Author: Jehan <jehan girinstud io>
Date:   Sun Jul 17 18:55:37 2022 +0200

    plug-ins: fix small memory leak from MR !627.

 plug-ins/file-tiff/file-tiff-save.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)
---
diff --git a/plug-ins/file-tiff/file-tiff-save.c b/plug-ins/file-tiff/file-tiff-save.c
index 80b6c4faa7..100aaa100b 100644
--- a/plug-ins/file-tiff/file-tiff-save.c
+++ b/plug-ins/file-tiff/file-tiff-save.c
@@ -681,7 +681,7 @@ save_layer (TIFF        *tif,
        * set it back to NULL and save the RGB profile instead
        */
       if (cmyk_profile && ! gimp_color_profile_is_cmyk (cmyk_profile))
-        cmyk_profile = NULL;
+        g_clear_object (&cmyk_profile);
 
       /* Write the RGB or CMYK color profile to the TIFF file */
       if (profile && ! config_cmyk)