staging: rtl8188eu: Remove function rtw_alloc_etherdev()

rtw_alloc_etherdev() is used in rtw_init_netdev() but never gets called
because old_padapter is never NULL.

Signed-off-by: navin patidar <navin.patidar@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>