scsi: ufs: Avoid to call REQ_CLKS_OFF to CLKS_OFF

Once UFS is gated with CLKS_OFF, it should not call REQ_CLKS_OFF
again. This can lead to hibern8_enter failure.

Link: https://lore.kernel.org/r/20201117165839.1643377-2-jaegeuk@kernel.org


Reviewed-by: Can Guo <cang@codeaurora.org>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>