ceph: exclude snapdir from readdir results

It was hidden from sync readdir, but not the cached dcache version.

Signed-off-by: Sage Weil <sage@newdream.net>
diff --git a/fs/ceph/dir.c b/fs/ceph/dir.c
index 4f74679..32ef543 100644
--- a/fs/ceph/dir.c
+++ b/fs/ceph/dir.c
@@ -131,6 +131,7 @@
 			goto out_unlock;
 		}
 		if (!d_unhashed(dentry) && dentry->d_inode &&
+		    ceph_snap(dentry->d_inode) != CEPH_SNAPDIR &&
 		    filp->f_pos <= di->offset)
 			break;
 		dout(" skipping %p %.*s at %llu (%llu)%s%s\n", dentry,