NFSv4: Fix nfs4_return_incompatible_delegation

The 'fmode' argument can take an FMODE_EXEC value, which we want to
filter out before comparing to the delegation type.
Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>

fs/nfs/nfs4proc.c

@@ -1669,6 +1669,7 @@ static void nfs4_return_incompatible_delegation(struct inode *inode, fmode_t fmo
 {
 	struct nfs_delegation *delegation;
 
+	fmode &= FMODE_READ|FMODE_WRITE;
 	rcu_read_lock();
 	delegation = rcu_dereference(NFS_I(inode)->delegation);
 	if (delegation == NULL || (delegation->type & fmode) == fmode) {