ANDROID: block: Improve shared tag set performance

Remove the code for fair tag sharing because it significantly hurts
performance for UFS devices. Removing this code is safe because the
legacy block layer worked fine without any equivalent fairness
algorithm.

This algorithm hurts performance for UFS devices because UFS devices
have multiple logical units. One of these logical units (WLUN) is used
to submit control commands, e.g. START STOP UNIT. If any request is
submitted to the WLUN, the queue depth is reduced from 31 to 15 or
lower for data LUNs.

See also https://lore.kernel.org/linux-scsi/20221229030645.11558-1-ed.tsai@mediatek.com/



Cc: Christoph Hellwig <hch@lst.de>
Cc: Martin K. Petersen <martin.petersen@oracle.com>
Cc: Ming Lei <ming.lei@redhat.com>
Cc: Keith Busch <kbusch@kernel.org>
Cc: Damien Le Moal <damien.lemoal@opensource.wdc.com>
Cc: Ed Tsai <ed.tsai@mediatek.com>
Change-Id: Ia6d75917d533f32fffc68348b52fd3d972c9074c
Signed-off-by: Bart Van Assche <bvanassche@acm.org>
Bug: 281845090
Link: https://lore.kernel.org/linux-block/20230103195337.158625-1-bvanassche@acm.org/


Signed-off-by: Bart Van Assche <bvanassche@google.com>