- Adjust the comment about re-routing PCI interrupts to be less   ia64-specific. - When trying to re-route interrupts, don't change cfg->intline if the   re-route fails by returning an invalid vector.  This fixes machines   without any way of routing interrupts such as older PC's without a   $PIR table.
- Adjust the comment about re-routing PCI interrupts to be less
  ia64-specific.
- When trying to re-route interrupts, don't change cfg->intline if the
  re-route fails by returning an invalid vector.  This fixes machines
  without any way of routing interrupts such as older PC's without a
  $PIR table.

We do not currently write the new intline value back to the hardware, but
we should.  That will likely be added in a later commit.

jrobhoward/SCADAbase,jrobhoward/SCADAbase,jrobhoward/SCADAbase,jrobhoward/SCADAbase,jrobhoward/SCADAbase,jrobhoward/SCADAbase,jrobhoward/SCADAbase,jrobhoward/SCADAbase,jrobhoward/SCADAbase,jrobhoward/SCADAbase,jrobhoward/SCADAbase