ocfs2: use actual name length when find entry in ocfs2_orphan_del()

If the namelen is 20 and name only has actual length 16, it will fail in
ocfs2_find_entry because of mismatch.  So use actual name length when find
entry.

Signed-off-by: Joseph Qi <joseph.qi@huawei.com>
Signed-off-by: Yiwen Jiang <jiangyiwen@huawei.com>
Cc: Mark Fasheh <mfasheh@suse.com>
Cc: Joel Becker <jlbec@evilplan.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>