Remove unused return value from signal_irq callback

Signed-off-by: Alex Dubov <oakad@yahoo.com>
Signed-off-by: Pierre Ossman <drzeus@drzeus.cx>
diff --git a/include/linux/tifm.h b/include/linux/tifm.h
index 9caa28e..5b0baef 100644
--- a/include/linux/tifm.h
+++ b/include/linux/tifm.h
@@ -91,7 +91,7 @@
 	tifm_media_id           media_id;
 	unsigned int            socket_id;
 
-	unsigned int            (*signal_irq)(struct tifm_dev *sock,
+	void                    (*signal_irq)(struct tifm_dev *sock,
 					      unsigned int sock_irq_status);
 
 	struct tifm_driver      *drv;