NFSv4: Add missing nfs_put_lock_context()

Otherwise the lock context won't be freed when we're done with it.

From: NeilBrown <neilb@suse.com>
Fixes: 5bd3f817 ("NFSv4: change nfs4_select_rw_stateid to take a lock_context inplace of lock_owner")
Signed-off-by: Anna Schumaker <Anna.Schumaker@netapp.com>
Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>

fs/nfs/nfs4proc.c

@@ -2955,8 +2955,10 @@ static int _nfs4_do_setattr(struct inode *inode,
 		l_ctx = nfs_get_lock_context(ctx);
 		if (IS_ERR(l_ctx))
 			return PTR_ERR(l_ctx);
-		if (nfs4_select_rw_stateid(ctx->state, FMODE_WRITE, l_ctx,
-				&arg->stateid, &delegation_cred) == -EIO)
+		status = nfs4_select_rw_stateid(ctx->state, FMODE_WRITE, l_ctx,
+						&arg->stateid, &delegation_cred);
+		nfs_put_lock_context(l_ctx);
+		if (status == -EIO)
 			return -EBADF;
 	} else
 		nfs4_stateid_copy(&arg->stateid, &zero_stateid);