Use the right predicate in ->atomic_open() instances

->atomic_open() can be given an in-lookup dentry *or* a negative one
found in dcache.  Use d_in_lookup() to tell one from another, rather
than d_unhashed().

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
diff --git a/fs/ceph/file.c b/fs/ceph/file.c
index ce2f579..0daaf7c 100644
--- a/fs/ceph/file.c
+++ b/fs/ceph/file.c
@@ -394,7 +394,7 @@
 	if ((flags & O_CREAT) && !req->r_reply_info.head->is_dentry)
 		err = ceph_handle_notrace_create(dir, dentry);
 
-	if (d_unhashed(dentry)) {
+	if (d_in_lookup(dentry)) {
 		dn = ceph_finish_lookup(req, dentry, err);
 		if (IS_ERR(dn))
 			err = PTR_ERR(dn);