[gimp/gimp-2-8] plug-ins: fix cherry-picked commit.

[Jehan Pagès <jehanp src gnome org>]

commit d21c0a96d27a0321c2683e24e1b2a069e79d988d
Author: Jehan <jehan girinstud io>
Date:   Fri Jan 5 22:46:59 2018 +0100

    plug-ins: fix cherry-picked commit.
    
    Well I knew that cherry-picking without proper build test was wrong! :P
    Commit 657a754f98eb9a67d8dcbc8c05a3e3a66fbee44f unref() a variable which
    does not exist in older GIMP 2.8 code.

 plug-ins/common/file-gbr.c |    2 +-
 1 files changed, 1 insertions(+), 1 deletions(-)
---
diff --git a/plug-ins/common/file-gbr.c b/plug-ins/common/file-gbr.c
index ae00a4a..5dc3074 100644
--- a/plug-ins/common/file-gbr.c
+++ b/plug-ins/common/file-gbr.c
@@ -417,7 +417,7 @@ load_image (const gchar  *filename,
         {
           g_set_error (error, G_FILE_ERROR, G_FILE_ERROR_FAILED,
                        _("Unsupported brush format"));
-          g_object_unref (input);
+          close (fd);
           return -1;
         }
       break;