scsi: ufs: core: Remove redundant wb check

We used to use the extended-feature field in the device descriptor as an
indication that the device supported UFS 2.2 or later.  Remove that as this
check is specifically done few lines above.

Signed-off-by: Arthur Simchaev <Arthur.Simchaev@wdc.com>
Reviewed-by: Bart Van Assche <bvanassche@acm.org>
Reviewed-by: Bean Huo <beanhuo@micron.com>
Reviewed-by: Stanley Chu <stanley.chu@mediatek.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>