ceph: do not set r_old_dentry_dir on link()
ceph: do not set r_old_dentry_dir on link()

This is racy--we do not know whather d_parent has changed out from
underneath us because i_mutex is not held on the source inode's directory.

Also, taking this reference is useless.

Reported-by: Al Viro <de609eb4d5d70b1d38ec6642adbfc33a2781f63c@zeniv.linux.org.uk>
Signed-off-by: Sage Weil <6dd34506bbd5e58221bbb3e4732d97c91f02277b@inktank.com>
Reviewed-by: Yan, Zheng <45e2ee8c8b09e76a9d512320d4eb53c0cd9925c0@intel.com>

KristFoundation/Programs,KristFoundation/Programs,KristFoundation/Programs,KristFoundation/Programs,KristFoundation/Programs,KristFoundation/Programs