LU-642 lov: make up obd_connect for inactive OSC

When OSC is inactivated before lov tries to connect it, lov_connect()
miss the chance to connect it to OST devices even when it is
activated later.

We need make up the connection for the initially inactive OSC when it
is activated.

Signed-off-by: Bobi Jam <bobijam.xu@intel.com>
Change-Id: I4aca442bc4a77baa2bc14adaf2b0f8f5c7bfa7df
Reviewed-on: http://review.whamcloud.com/4691
Tested-by: Hudson
Tested-by: Maloo <whamcloud.maloo@gmail.com>
Reviewed-by: Lai Siyao <lai.siyao@intel.com>
Reviewed-by: Jinshan Xiong <jinshan.xiong@intel.com>
Reviewed-by: Oleg Drokin <oleg.drokin@intel.com>