staging: olpc_dcon: Deletion of a check before backlight_device_unregister()

The backlight_device_unregister() function tests whether its argument is NULL
and then returns immediately. Thus the test around the call is not needed.

This issue was detected by using the Coccinelle software.

Signed-off-by: Markus Elfring <elfring@users.sourceforge.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/staging/olpc_dcon/olpc_dcon.c

@@ -682,8 +682,7 @@ static int dcon_remove(struct i2c_client *client)
 
 	free_irq(DCON_IRQ, dcon);
 
-	if (dcon->bl_dev)
-		backlight_device_unregister(dcon->bl_dev);
+	backlight_device_unregister(dcon->bl_dev);
 
 	if (dcon_device != NULL)
 		platform_device_unregister(dcon_device);