hpsa: remove unused parameter hostno

This parameter was once used before scan_start was defined
but now it is no longer used.

Signed-off-by: Don Brace <don.brace@pmcs.com>
Reviewed-by: Tomas Henzl <thenzl@redhat.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>