pNFS: Fix an unused variable warning in pnfs_roc_get_barrier

Signed-off-by: Trond Myklebust <[e-mail]>

fs/nfs/pnfs.c

···
 {
 	struct nfs_inode *nfsi = NFS_I(ino);
 	struct pnfs_layout_hdr *lo;
-	nfs4_stateid stateid;
 	u32 current_seqid;
 
 	spin_lock(&ino->i_lock);
···
 	 * a barrier, we choose the worst-case barrier.
 	 */
 	*barrier = current_seqid + atomic_read(&lo->plh_outstanding);
-	stateid = lo->plh_stateid;
 	spin_unlock(&ino->i_lock);
 }