sparseirq, powerpc/cell: fix unused variable warning in interrupt.c

This new compiler warning:

   arch/powerpc/platforms/cell/interrupt.c: In function 'handle_iic_irq':
   arch/powerpc/platforms/cell/interrupt.c:240: warning: unused variable 'cpu'

Triggers because the local variable 'cpu' became unused due to commit:

   dee4102a: sparseirq: use kstat_irqs_cpu instead

Remove the variable.
Signed-off-by: Stephen Rothwell <sfr@canb.auug.org.au>
Cc: Yinghai Lu <yinghai@kernel.org>
Cc: ppc-dev <linuxppc-dev@ozlabs.org>
LKML-Reference: <20090316185256.4a160374.sfr@canb.auug.org.au>
Signed-off-by: Ingo Molnar <mingo@elte.hu>

arch/powerpc/platforms/cell/interrupt.c

@@ -237,8 +237,6 @@ extern int noirqdebug;
 
 static void handle_iic_irq(unsigned int irq, struct irq_desc *desc)
 {
-	const unsigned int cpu = smp_processor_id();
-
 	spin_lock(&desc->lock);
 
 	desc->status &= ~(IRQ_REPLAY | IRQ_WAITING);