apic_irq() returns -1 when there is no match for (IOAPIC, intpin) pair.
apic_irq() returns -1 when there is no match for (IOAPIC, intpin) pair.

Adjust some comments to better match the code.

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