IRQ: Use the new typedef for interrupt handler function pointers

Use the new typedef for interrupt handler function pointers rather than
actually spelling out the full thing each time.  This was scripted with the
following small shell script:

#!/bin/sh
egrep -nHrl -e 'irqreturn_t[ 	]*[(][*]' $* |
while read i
do
    echo $i
    perl -pi -e 's/irqreturn_t\s*[(]\s*[*]\s*([_a-zA-Z0-9]*)\s*[)]\s*[(]\s*int\s*,\s*void\s*[*]\s*[)]/irq_handler_t \1/g' $i || exit $?
done

Signed-Off-By: David Howells <dhowells@redhat.com>
diff --git a/arch/powerpc/kernel/ibmebus.c b/arch/powerpc/kernel/ibmebus.c
index da9fe25..39db7a3 100644
--- a/arch/powerpc/kernel/ibmebus.c
+++ b/arch/powerpc/kernel/ibmebus.c
@@ -319,7 +319,7 @@
 
 int ibmebus_request_irq(struct ibmebus_dev *dev,
 			u32 ist, 
-			irqreturn_t (*handler)(int, void*),
+			irq_handler_t handler,
 			unsigned long irq_flags, const char * devname,
 			void *dev_id)
 {