Simplify recording command completion time in __ufshcd_transfer_req_compl()
by assigning lrbp->compl_time_stamp in a unified location.

Link: https://lore.kernel.org/r/20200706060707.32608-2-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>