Which vector an irq is assigned to now varies dynamically and is
not needed outside of io_apic.c.  So remove the possibility
of accessing the information outside of io_apic.c and remove
the silly macro that makes looking for users of irq_vector
difficult.

The fact this compiles ensures there aren't any more pieces
of the old CONFIG_PCI_MSI weirdness that I failed to remove.
Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>