Add proper error handling for osd_req_op_cls_init() to replace
BUG_ON statement when failing from memory allocation.
Signed-off-by: NChengguang Xu <cgxu519@gmx.com>
Reviewed-by: NIlya Dryomov <idryomov@gmail.com>
Signed-off-by: NIlya Dryomov <idryomov@gmail.com>