scsi: ufs: Simplify two tests

lrbp->cmd is set only for SCSI commands. Use this knowledge to simplify two
boolean expressions.

Link: https://lore.kernel.org/r/20200123035637.21848-4-bvanassche@acm.org


Cc: Alim Akhtar <alim.akhtar@samsung.com>
Cc: Tomas Winkler <tomas.winkler@intel.com>
Cc: Bean Huo <beanhuo@micron.com>
Cc: Can Guo <cang@codeaurora.org>
Reviewed-by: Stanley Chu <stanley.chu@mediatek.com>
Reviewed-by: Asutosh Das <asutoshd@codeaurora.org>
Reviewed-by: Avri Altman <avri.altman@wdc.com>
Signed-off-by: Bart Van Assche <bvanassche@acm.org>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>