[SCSI] pm80xx: Tasklets synchronization fix.

When multiple vectors are used, the vector variable is over written,
resulting in unhandled operation for those vectors.
This fix prevents the problem by maitaining HBA instance and
vector values for each irq.

[jejb: checkpatch fixes]
Signed-off-by:  <Nikith.Ganigarakoppal@pmcs.com>
Signed-off-by:  <Anandkumar.Santhanam@pmcs.com>
Reviewed-by: Jack Wang <jinpu.wang@profitbricks.com>
Signed-off-by: James Bottomley <JBottomley@Parallels.com>