x86/ioapic.c: clean up replace_pin_at_irq_node logic and comments
x86/ioapic.c: clean up replace_pin_at_irq_node logic and comments

There's no need for a control variable in replace_pin_at_irq_node();
it can just return if it finds the old apic/pin to replace.

If the loop terminates, then it didn't find the old apic/pin, so it can
add the new ones.

Signed-off-by: Jeremy Fitzhardinge <35cfe9f678a9e9bbdcf2f6e68cd105ce06d149b1@citrix.com>

TeamVee-Kanas/android_kernel_samsung_kanas,KristFoundation/Programs,KristFoundation/Programs,TeamVee-Kanas/android_kernel_samsung_kanas,KristFoundation/Programs,TeamVee-Kanas/android_kernel_samsung_kanas,KristFoundation/Programs,KristFoundation/Programs,TeamVee-Kanas/android_kernel_samsung_kanas,TeamVee-Kanas/android_kernel_samsung_kanas,KristFoundation/Programs