ceph: remove ceph_lookup_inode()

commit 6f60f889 (ceph: fix freeing inode vs removing session caps race)
introduced ceph_lookup_inode(). But there is already a ceph_find_inode()
which provides similar function. So remove ceph_lookup_inode(), use
ceph_find_inode() instead.

Signed-off-by: Yan, Zheng <zheng.z.yan@intel.com>
Reviewed-by: Alex Elder <alex.elder@linary.org>
Reviewed-by: Sage Weil <sage@inktank.com>

fs/ceph/mds_client.c

@@ -1054,7 +1054,7 @@ static void remove_session_caps(struct ceph_mds_session *session)
 			vino = cap->ci->i_vino;
 			spin_unlock(&session->s_cap_lock);
 
-			inode = ceph_lookup_inode(sb, vino);
+			inode = ceph_find_inode(sb, vino);
 			iput(inode);
 
 			spin_lock(&session->s_cap_lock);