Add missing setup_xfer_req() call in ufshcd_issue_devman_upiu_cmd() in
ufs-bsg path. Relocate existing setup_xfer_req() calls to a common place,
i.e., ufshcd_send_command(), to simplify the driver.

Link: https://lore.kernel.org/r/20200706060707.32608-3-stanley.chu@mediatek.comAcked-by: NAvri Altman <Avri.Altman@wdc.com>
Signed-off-by: NStanley Chu <stanley.chu@mediatek.com>
Signed-off-by: NMartin K. Petersen <martin.petersen@oracle.com>