ocfs2: remove set but not used variable 'last_hash'

ocfs2: remove set but not used variable 'last_hash'

Fixes gcc '-Wunused-but-set-variable' warning:

  fs/ocfs2/xattr.c: In function ocfs2_xattr_bucket_find:
  fs/ocfs2/xattr.c:3828:6: warning: variable last_hash set but not used [-Wunused-but-set-variable]

It's never used and can be removed.

Link: http://lkml.kernel.org/r/20190716132110.34836-1-yuehaibing@huawei.com
Signed-off-by: YueHaibing <yuehaibing@huawei.com>
Acked-by: Joseph Qi <joseph.qi@linux.alibaba.com>
Cc: Mark Fasheh <mark@fasheh.com>
Cc: Joel Becker <jlbec@evilplan.org>
Cc: Junxiao Bi <junxiao.bi@oracle.com>
Cc: Changwei Ge <gechangwei@live.cn>
Cc: Gang He <ghe@suse.com>
Cc: Jun Piao <piaojun@huawei.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>