libata: make ata_pci_init_one() not use ops->irq_handler and pi->sht

ata_pci_init_one() is the only function which uses ops->irq_handler
and pi->sht.  Other initialization functions take the same information
as arguments.  This causes confusion and duplicate unused entries in
structures.

Make ata_pci_init_one() take sht as an argument and use ata_interrupt
implicitly.  All current users use ata_interrupt and if different irq
handler is necessary open coding ata_pci_init_one() using
ata_prepare_sff_host() and ata_activate_sff_host can be done under ten
lines including error handling and driver which requires custom
interrupt handler is likely to require custom initialization anyway.

As ata_pci_init_one() was the last user of ops->irq_handler, this
patch also kills the field.

Signed-off-by: Tejun Heo <htejun@gmail.com>

drivers/ata/libata-core.c

@@ -109,7 +109,6 @@ const struct ata_port_operations ata_sff_port_ops = {
 	.irq_on			= ata_irq_on,
 
 	.port_start		= ata_sff_port_start,
-	.irq_handler		= ata_interrupt,
 };
 
 const struct ata_port_operations ata_bmdma_port_ops = {