LU-1772 lov: lock with lov lsm refcount taken may deadlock

LU-1772 lov: lock with lov lsm refcount taken may deadlock

lov_io_init() and lov_lock_init() has taken lsm refcount, no need to
lock lo_type_guard otherwise it may lead to deadlock.

Signed-off-by: Lai Siyao <laisiyao@whamcloud.com>
Change-Id: I3e953d41e181c3ef19f7bf8d92d9791753d4c58a
Reviewed-on: http://review.whamcloud.com/3807
Reviewed-by: Jinshan Xiong <jinshan.xiong@whamcloud.com>
Tested-by: Hudson
Tested-by: Maloo <whamcloud.maloo@gmail.com>
Reviewed-by: Fan Yong <yong.fan@whamcloud.com>
Reviewed-by: Oleg Drokin <green@whamcloud.com>