Eliminate pointless casts from void* in a few driver irq handlers.

Signed-off-by: Jeff Garzik <jgarzik@redhat.com>
diff --git a/drivers/mtd/onenand/onenand_base.c b/drivers/mtd/onenand/onenand_base.c
index dd28355..1b0b320 100644
--- a/drivers/mtd/onenand/onenand_base.c
+++ b/drivers/mtd/onenand/onenand_base.c
@@ -359,7 +359,7 @@
  */
 static irqreturn_t onenand_interrupt(int irq, void *data)
 {
-	struct onenand_chip *this = (struct onenand_chip *) data;
+	struct onenand_chip *this = data;
 
 	/* To handle shared interrupt */
 	if (!this->complete.done)