EDAC: add __init to i7core_xeon_pci_fixup

It's called only from an __init function and is the only user
of pcibios_scan_specific_bus which will be marked as __devinit in
the next patch.

Signed-off-by: Jiri Slaby <jslaby@suse.cz>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>