rtl8723bs: rtnl_is_locked() misuse

[Kirill Tkhai]

Hi,

I'm reporting you about misuse of rtnl_is_locked() in rtw_change_ifname() 
function.
Note, that rtnl_is_locked() *does not mean* rtnl is locked on the *current cpu*.
This primitive returns true in case of rtnl is locked somewhere in the system.
So, it can't be used in the below code:

if (!rtnl_is_locked())
                unregister_netdev(cur_pnetdev);
        else
                unregister_netdevice(cur_pnetdev);

Kirill