pata_bf54x: fix return type of bfin_set_devctl

The new devctl func added for us to the driver has the wrong return
type.  Which is to say there shouldn't be any.  This fixes compile
time warnings as there shouldn't be any runtime difference.
Signed-off-by: NMike Frysinger <vapier@gentoo.org>
Signed-off-by: NJeff Garzik <jgarzik@redhat.com>

drivers/ata/pata_bf54x.c

@@ -826,7 +826,7 @@ static void bfin_dev_select(struct ata_port *ap, unsigned int device)
  *	@ctl: value to write
  */
 
-static u8 bfin_set_devctl(struct ata_port *ap, u8 ctl)
+static void bfin_set_devctl(struct ata_port *ap, u8 ctl)
 {
 	void __iomem *base = (void __iomem *)ap->ioaddr.ctl_addr;
 	write_atapi_register(base, ATA_REG_CTRL, ctl);