[PARPORT] Kill useful 'irq' arg from parport_{generic_irq,ieee1284_interrupt}

parport_ieee1284_interrupt() was not using its first arg at all.
Delete.

parport_generic_irq()'s second arg makes its first arg completely
redundant.  Delete, and use port->irq in the one place where we actually
need it.

Also, s/__inline__/inline/ to make the code look nicer.

Signed-off-by: Jeff Garzik <jgarzik@redhat.com>