[SPARC, XEN, NET/CXGB3] use irq_handler_t where appropriate

Rather than hand-rolling our own prototype, make the code more
future-proof by using the standard irq_handler_t typedef.

Signed-off-by: Jeff Garzik <jgarzik@redhat.com>
diff --git a/arch/x86/xen/events.c b/arch/x86/xen/events.c
index da1b173..6d1da58 100644
--- a/arch/x86/xen/events.c
+++ b/arch/x86/xen/events.c
@@ -383,7 +383,7 @@
 }
 
 int bind_evtchn_to_irqhandler(unsigned int evtchn,
-			      irqreturn_t (*handler)(int, void *),
+			      irq_handler_t handler,
 			      unsigned long irqflags,
 			      const char *devname, void *dev_id)
 {
@@ -402,7 +402,7 @@
 EXPORT_SYMBOL_GPL(bind_evtchn_to_irqhandler);
 
 int bind_virq_to_irqhandler(unsigned int virq, unsigned int cpu,
-			    irqreturn_t (*handler)(int, void *),
+			    irq_handler_t handler,
 			    unsigned long irqflags, const char *devname, void *dev_id)
 {
 	unsigned int irq;