The pending interrupt check code is mixed with the local APIC setup code,
that looks messy.

Extract the related code, move it into a new function named
apic_pending_intr_clear().
Signed-off-by: NDou Liyang <douly.fnst@cn.fujitsu.com>
Signed-off-by: NThomas Gleixner <tglx@linutronix.de>
Reviewed-by: NAndy Shevchenko <andy.shevchenko@gmail.com>
Cc: bhe@redhat.com
Cc: ebiederm@xmission.com
Link: https://lkml.kernel.org/r/20180301055930.2396-2-douly.fnst@cn.fujitsu.com