KVM: x86: ioapic: Remove redundant check for Remote IRR in ioapic_set_irq

Remote IRR for level-triggered interrupts was previously checked in
ioapic_set_irq, but since we now have a check in ioapic_service we
can remove the redundant check from ioapic_set_irq.

This commit doesn't change semantics.

Signed-off-by: Nikita Leshenko <nikita.leshchenko@oracle.com>
Reviewed-by: Liran Alon <liran.alon@oracle.com>
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Reviewed-by: Wanpeng Li <wanpeng.li@hotmail.com>
Signed-off-by: Radim Krčmář <rkrcmar@redhat.com>