LU-1682 ptlrpc: LBUG in ldlm_cli_cancel_local

LU-1682 ptlrpc: LBUG in ldlm_cli_cancel_local

When the case ldlm_cli_enqueue() created a new lock, and then, fails
to allocate memory for a new request, it could cause the LBUG in
ldlm_cli_cancel_local() because the lock->l_conn_export is NULL,
nevertheless the lock is a client-side lock.
This patch fills in some lock fields before the memory allocation
for a new request.

Signed-off-by: Hiroya Nozaki <nozaki.hiroya@jp.fujitsu.com>
Change-Id: I4ba4b6f1bc5dfbb51853261a0f247289304a6abd
Reviewed-on: http://review.whamcloud.com/3488
Tested-by: Hudson
Tested-by: Maloo <whamcloud.maloo@gmail.com>
Reviewed-by: Oleg Drokin <green@whamcloud.com>
Reviewed-by: Jinshan Xiong <jinshan.xiong@whamcloud.com>