staging: olpc_dcon: return NOTIFY_DONE instead of the 0.

return a valid macro instead of 0 (as #define NOTIFY_DONE 0)
in the reboot callback

Signed-off-by: Devendra Naga <devendra.aaru@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/staging/olpc_dcon/olpc_dcon.c

@@ -550,12 +550,12 @@ static int dcon_reboot_notify(struct notifier_block *nb,
 	struct dcon_priv *dcon = container_of(nb, struct dcon_priv, reboot_nb);
 
 	if (!dcon || !dcon->client)
-		return 0;
+		return NOTIFY_DONE;
 
 	/* Turn off the DCON. Entirely. */
 	dcon_write(dcon, DCON_REG_MODE, 0x39);
 	dcon_write(dcon, DCON_REG_MODE, 0x32);
-	return 0;
+	return NOTIFY_DONE;
 }
 
 static int unfreeze_on_panic(struct notifier_block *nb,