x86/ioapic.c: simplify add_pin_to_irq_node()
x86/ioapic.c: simplify add_pin_to_irq_node()

Rather than duplicating the same alloc/init code twice, restructure
the function to look for duplicates and then add an entry
if none is found.

This function is not performance critical; all but one of its callers
are __init functions, and the non-__init caller is for PCI device setup.

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

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