scsi: pm80xx: Use bitmap_zalloc() for tags bitmap allocation

We used to allocate X bytes while we only need X bits.

Link: https://lore.kernel.org/r/20211101232825.2350233-5-ipylypiv@google.com


Reviewed-by: Vishakha Channapattan <vishakhavc@google.com>
Acked-by: Jack Wang <jinpu.wang@ionos.com>
Signed-off-by: Igor Pylypiv <ipylypiv@google.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>