[PATCH] PCI: cleanup unused variable about msi driver

In IA64 platform, msi driver does not use irq_vector variable, and in
x86 platform LAST_DEVICE_VECTOR should one before FIRST_SYSTEM_VECTOR,
this patch modify this.

Signed-off-by: bibo, mao <bibo.mao@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>