ide: initialize rq->cmd_type in ide_init_drive_cmd() callers

* Initialize rq->cmd_type in ide_wait_cmd(), ide_cmd_ioctl() and
  set_pio_mode() (other callers were aleady over-riding rq->cmd_type).

* Remove no longer needed rq->cmd_type setup from ide_init_drive_cmd().

Acked-by: Sergei Shtylyov <sshtylyov@ru.mvista.com>
Signed-off-by: Bartlomiej Zolnierkiewicz <bzolnier@gmail.com>