NFSv4: Ensure that we pass the correct dentry to nfs4_intent_set_file

This patch fixes an Oops that was reported by Gabriel Barazer.
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>

fs/nfs/nfs4proc.c

@@ -1434,7 +1434,7 @@ nfs4_atomic_open(struct inode *dir, struct dentry *dentry, struct nameidata *nd)
 	}
 	res = d_add_unique(dentry, igrab(state->inode));
 	if (res != NULL)
-		dentry = res;
+		path.dentry = res;
 	nfs4_intent_set_file(nd, &path, state);
 	return res;
 }