On the unlikely event that drv is null, the current code will
perform a null pointer dereference with it when printing a dev_dbg
message.  Instead, the BUG_ON check on drv should be performed
before we emit the dev_dbg message.
Signed-off-by: Colin Ian King <colin.king@canonical.com>
Signed-off-by: Geoff Levand <geoff@infradead.org>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
        dev_dbg(&dev->core, "%s:%d\n", __func__, __LINE__);
 
        drv = ps3_system_bus_dev_to_vuart_drv(dev);
+       BUG_ON(!drv);
 
        dev_dbg(&dev->core, "%s:%d: (%s)\n", __func__, __LINE__,
                drv->core.core.name);
 
-       BUG_ON(!drv);
-
        if (dev->port_number >= PORT_COUNT) {
                BUG();
                return -EINVAL;