NFSv4: Return delegations synchronously in evict_inode

Kinglong Mee reports that asynchronous delegations are being killed
by the call to rpc_shutdown_client() when unmounting. This can lead
to state leakage on the server until the client lease expires.

Reported-by: Kinglong Mee <kinglongmee@gmail.com>
Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>

fs/nfs/delegation.c

@@ -514,7 +514,7 @@ void nfs_inode_return_delegation_noreclaim(struct inode *inode)
 
 	delegation = nfs_inode_detach_delegation(inode);
 	if (delegation != NULL)
-		nfs_do_return_delegation(inode, delegation, 0);
+		nfs_do_return_delegation(inode, delegation, 1);
 }
 
 /**