[gdk-pixbuf] tests: Fix a missing error handling block

[Bastien Nocera <hadess src gnome org>]

commit b2b23b06545c15d322c875dc439773c990619e37
Author: Philip Withnall <philip tecnocode co uk>
Date:   Mon Dec 12 22:12:27 2016 +0000

    tests: Fix a missing error handling block
    
    err could never be set here, meaning we were missing out on some error
    checking. The test still passes.
    
    Coverity CID 1388525.
    
    https://bugzilla.gnome.org/show_bug.cgi?id=776020

 tests/pixbuf-lowmem.c |    2 +-
 1 files changed, 1 insertions(+), 1 deletions(-)
---
diff --git a/tests/pixbuf-lowmem.c b/tests/pixbuf-lowmem.c
index 9e9571f..b34e527 100644
--- a/tests/pixbuf-lowmem.c
+++ b/tests/pixbuf-lowmem.c
@@ -133,7 +133,7 @@ mem_test (const gchar *bytes, gsize len)
        err = NULL;
        did_fail = TRUE;
       }
-    gdk_pixbuf_loader_close (loader, NULL);
+    gdk_pixbuf_loader_close (loader, &err);
     if (err)
       {
        g_error_free (err);