exofs: remove unnecessary dentry_unhash on rmdir/rename_dir
exofs: remove unnecessary dentry_unhash on rmdir/rename_dir

Exofs has no problems with lingering references to unlinked directory
inodes.

CC: Benny Halevy <23c997c90eb8537635e9392d48e7af1bf1b2ca22@panasas.com>
CC: a82a4ea26eab90f7ac42fa99b81e4ef39828169e@open-osd.org
Acked-by: Boaz Harrosh <c7aa24d52dd751aba44a7843602dc14649cc8bce@panasas.com>
Signed-off-by: Sage Weil <6dd34506bbd5e58221bbb3e4732d97c91f02277b@newdream.net>
Signed-off-by: Al Viro <de609eb4d5d70b1d38ec6642adbfc33a2781f63c@zeniv.linux.org.uk>

KristFoundation/Programs,TeamVee-Kanas/android_kernel_samsung_kanas,TeamVee-Kanas/android_kernel_samsung_kanas,TeamVee-Kanas/android_kernel_samsung_kanas,KristFoundation/Programs,KristFoundation/Programs,KristFoundation/Programs,KristFoundation/Programs,TeamVee-Kanas/android_kernel_samsung_kanas,KristFoundation/Programs,TeamVee-Kanas/android_kernel_samsung_kanas