x86: io-apic - do not use KERN_DEBUG marker too much, fix

Yinghai Lu reported:

| >  0 add_pin_to_irq: irq 15 --> apic 0 pin 15
| > IOAPIC[0]: Set routing entry (8-15 -> 0x3f -> IRQ 15 Mode:0 Active:0)
| >  8-16 8-17 8-18 8-19 8-20 8-21 8-22 8-23 (apicid-pin) not connected
| >  9-0 9-1 9-2 9-3 9-4 9-5 9-6 9-7 9-8 9-9 9-10 9-11 9-12 9-13 9-14 9-15
| > 9-16 9-17 9-18 9-19 9-20 9-21 9-22 9-23 (apicid-pin) not connected
| >
|
| only first one not connected at first, and ...

here is a quick fix for this.

Signed-off-by: Cyrill Gorcunov <gorcunov@gmail.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>