powerpc: Irq: Use generic_handle_irq

No functional change
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: ppc <linuxppc-dev@lists.ozlabs.org>
Link: http://lkml.kernel.org/r/20140223212736.333718121@linutronix.deSigned-off-by: Thomas Gleixner <tglx@linutronix.de>

arch/powerpc/kernel/irq.c

@@ -465,7 +465,6 @@ static inline void check_stack_overflow(void)
 
 void __do_irq(struct pt_regs *regs)
 {
-	struct irq_desc *desc;
 	unsigned int irq;
 
 	irq_enter();
@@ -487,11 +486,8 @@ void __do_irq(struct pt_regs *regs)
 	/* And finally process it */
 	if (unlikely(irq == NO_IRQ))
 		__get_cpu_var(irq_stat).spurious_irqs++;
-	else {
-		desc = irq_to_desc(irq);
-		if (likely(desc))
-			desc->handle_irq(irq, desc);
-	}
+	else
+		generic_handle_irq(irq);
 
 	trace_irq_exit(regs);