scsi: ufs: Update comment in the function ufshcd_wb_probe()

USFHCD supports both WriteBooster "LU dedicated buffer" mode and "shared
buffer" mode. Update the comment accordingly in the function
ufshcd_wb_probe().

Link: https://lore.kernel.org/r/20210119163847.20165-4-huobean@gmail.com


Reviewed-by: Can Guo <cang@codeaurora.org>
Reviewed-by: Stanley Chu <stanley.chu@mediatek.com>
Signed-off-by: Bean Huo <beanhuo@micron.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>