scsi: pm8001: Fix tag values handling

scsi: pm8001: Fix tag values handling

The function pm8001_tag_alloc() determines free tags using the function
find_first_zero_bit() which can return 0 when the first bit of the bitmap
being inspected is 0. As such, tag 0 is a valid tag value that should not
be dismissed as invalid. Fix the functions pm8001_work_fn(),
mpi_sata_completion(), pm8001_mpi_task_abort_resp() and
pm8001_open_reject_retry() to not dismiss 0 tags as invalid.

The value 0xffffffff is used for invalid tags for unused ccb information
structures. Add the macro definition PM8001_INVALID_TAG to define this
value.

Link: https://lore.kernel.org/r/20220220031810.738362-20-damien.lemoal@opensource.wdc.com
Reviewed-by: Jack Wang <jinpu.wang@ionos.com>
Signed-off-by: Damien Le Moal <damien.lemoal@opensource.wdc.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>