x86: I/O APIC: fix the name of the through-8259A handler

When the through-8259A mode is used for the timer, the call to
set_irq_handler() will register a NULL handler name, resulting in
"IO-APIC-<NULL>" reported.  Fix by calling ioapic_register_intr() as done
for all the other I/O APIC interrupts.

The 64-bit variation calls set_irq_chip_and_handler_name() here
needlessly and should get fixed with the upcoming merge.
Signed-off-by: Maciej W. Rozycki <macro@linux-mips.org>
Signed-off-by: Ingo Molnar <mingo@elte.hu>

arch/x86/kernel/io_apic_32.c

@@ -1331,8 +1331,7 @@ static void __init setup_ExtINT_IRQ0_pin(unsigned int apic, unsigned int pin, in
 	 * The timer IRQ doesn't have to know that behind the
 	 * scene we have a 8259A-master in AEOI mode ...
 	 */
-	irq_desc[0].chip = &ioapic_chip;
-	set_irq_handler(0, handle_edge_irq);
+	ioapic_register_intr(0, vector, IOAPIC_EDGE);
 
 	/*
 	 * Add it to the IO-APIC irq-routing table: