[netdrvr] irq handler minor cleanups in several drivers

* use irq_handler_t where appropriate

* no need to use 'irq' function arg, its already stored in a data struct

* rename irq handler 'irq' argument to 'dummy', where the function
  has been analyzed and proven not to use its first argument.

* remove always-false "dev_id == NULL" test from irq handlers

* remove pointless casts from void*

* declance: irq argument is not const

* add KERN_xxx printk prefix

* fix minor whitespace weirdness

Signed-off-by: Jeff Garzik <jgarzik@redhat.com>
diff --git a/drivers/net/wireless/libertas/if_cs.c b/drivers/net/wireless/libertas/if_cs.c
index ba4fc2b..d383c0f 100644
--- a/drivers/net/wireless/libertas/if_cs.c
+++ b/drivers/net/wireless/libertas/if_cs.c
@@ -243,7 +243,7 @@
 
 static irqreturn_t if_cs_interrupt(int irq, void *data)
 {
-	struct if_cs_card *card = (struct if_cs_card *)data;
+	struct if_cs_card *card = data;
 	u16 int_cause;
 
 	lbs_deb_enter(LBS_DEB_CS);