NFSv4.1: Use layout credentials for get_deviceinfo calls

This is not strictly needed, since get_deviceinfo is not allowed to
return NFS4ERR_ACCESS or NFS4ERR_WRONG_CRED, but lets do it anyway
for consistency with other pNFS operations.

Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
diff --git a/fs/nfs/objlayout/objlayout.c b/fs/nfs/objlayout/objlayout.c
index a9ebd81..1989908 100644
--- a/fs/nfs/objlayout/objlayout.c
+++ b/fs/nfs/objlayout/objlayout.c
@@ -614,7 +614,8 @@
 	pd.pglen = PAGE_SIZE;
 	pd.mincount = 0;
 
-	err = nfs4_proc_getdeviceinfo(NFS_SERVER(pnfslay->plh_inode), &pd);
+	err = nfs4_proc_getdeviceinfo(NFS_SERVER(pnfslay->plh_inode), &pd,
+			pnfslay->plh_lc_cred);
 	dprintk("%s nfs_getdeviceinfo returned %d\n", __func__, err);
 	if (err)
 		goto err_out;