scsi: ufs: core: Simplify power management during async scan

scsi: ufs: core: Simplify power management during async scan

ufshcd_init() calls pm_runtime_get_sync() before it calls
async_schedule(). ufshcd_async_scan() calls pm_runtime_put_sync() directly
or indirectly from ufshcd_add_lus(). Simplify ufshcd_async_scan() by always
calling pm_runtime_put_sync() from ufshcd_async_scan().

Cc: <stable@vger.kernel.org>
Signed-off-by: Bart Van Assche <bvanassche@acm.org>
Link: https://lore.kernel.org/r/20231218225229.2542156-2-bvanassche@acm.org
Reviewed-by: Can Guo <quic_cang@quicinc.com>
Reviewed-by: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>