[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/sparc/kernel/irq.c b/arch/sparc/kernel/irq.c
index 722d67d..e1e24f3 100644
--- a/arch/sparc/kernel/irq.c
+++ b/arch/sparc/kernel/irq.c
@@ -479,7 +479,7 @@
 
 extern void floppy_hardint(void);
 
-static irqreturn_t (*floppy_irq_handler)(int irq, void *dev_id);
+static irq_handler_t floppy_irq_handler;
 
 void sparc_floppy_irq(int irq, void *dev_id, struct pt_regs *regs)
 {
@@ -500,7 +500,7 @@
 }
 
 int sparc_floppy_request_irq(int irq, unsigned long flags,
-			     irqreturn_t (*irq_handler)(int irq, void *))
+			     irq_handler_t irq_handler)
 {
 	floppy_irq_handler = irq_handler;
 	return request_fast_irq(irq, floppy_hardint, flags, "floppy");