pc: Drop useless test from isa_irq_handler

IsaIrqState::ioapic is always non-NULL. Probably, the concrete
qemu_irq was supposed to be tested, but that's already done by
qemu_set_irq.
Signed-off-by: NJan Kiszka <jan.kiszka@siemens.com>
Signed-off-by: NBlue Swirl <blauwirbel@gmail.com>

hw/pc.c

@@ -96,9 +96,8 @@ void isa_irq_handler(void *opaque, int n, int level)
     if (n < 16) {
         qemu_set_irq(isa->i8259[n], level);
     }
-    if (isa->ioapic)
-        qemu_set_irq(isa->ioapic[n], level);
-};
+    qemu_set_irq(isa->ioapic[n], level);
+}
 
 static void ioport80_write(void *opaque, uint32_t addr, uint32_t data)
 {