Fix misplaced kfree from xlated_setup_gnttab_pages

[Dave Jones <davej@redhat.com>]

Passing a freed 'pages' to free_xenballooned_pages will end badly
on kernels with slub debug enabled.

This looks out of place between the rc assign and the check, and
was likely a cut-and-paste error.

Signed-off-by: Dave Jones <davej@fedoraproject.org>

diff --git a/arch/x86/xen/grant-table.c b/arch/x86/xen/grant-table.c
index 103c93f874b2..28990cc97304 100644
--- a/arch/x86/xen/grant-table.c
+++ b/arch/x86/xen/grant-table.c
@@ -161,12 +161,11 @@ static int __init xlated_setup_gnttab_pages(void)
 
 	rc = arch_gnttab_map_shared(pfns, nr_grant_frames, nr_grant_frames,
 				    &xen_auto_xlat_grant_frames.vaddr);
-
-	kfree(pages);
 	if (rc) {
 		pr_warn("%s Couldn't map %ld pfns rc:%d\n", __func__,
 			nr_grant_frames, rc);
 		free_xenballooned_pages(nr_grant_frames, pages);
+		kfree(pages);
 		kfree(pfns);
 		return rc;
 	}