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/um/kernel/irq.c b/arch/um/kernel/irq.c
index 3c01c2b..ef25956 100644
--- a/arch/um/kernel/irq.c
+++ b/arch/um/kernel/irq.c
@@ -364,7 +364,7 @@
 }
 
 int um_request_irq(unsigned int irq, int fd, int type,
-		   irqreturn_t (*handler)(int, void *),
+		   irq_handler_t handler,
 		   unsigned long irqflags, const char * devname,
 		   void *dev_id)
 {
@@ -425,7 +425,7 @@
 	}
 }
 
-int init_aio_irq(int irq, char *name, irqreturn_t (*handler)(int, void *))
+int init_aio_irq(int irq, char *name, irq_handler_t handler)
 {
 	int fds[2], err;