cpumask: remove references to struct irqaction's mask field.

Impact: cleanup

It's unused, since about 1995.  So remove all initialization of it in
preparation for actually removing the field.

Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
Acked-by: Thomas Gleixner <tglx@linutronix.de>

arch/sparc/kernel/sun4d_irq.c

@@ -326,7 +326,6 @@ int sun4d_request_irq(unsigned int irq,
 
 	action->handler = handler;
 	action->flags = irqflags;
-	cpus_clear(action->mask);
 	action->name = devname;
 	action->next = NULL;
 	action->dev_id = dev_id;