skdev->pdev and skdev->pdev->bus are always different than NULL in
skd_do_inq_page_da() so simplify the code accordingly.

Also cache skdev->pdev value in pdev variable while at it.

Cc: Akhil Bhansali <abhansali@stec-inc.com>
Cc: Jeff Moyer <jmoyer@redhat.com>
Signed-off-by: NBartlomiej Zolnierkiewicz <b.zolnierkie@samsung.com>
Signed-off-by: NKyungmin Park <kyungmin.park@samsung.com>
Signed-off-by: NJens Axboe <axboe@kernel.dk>