staging: rtl8188eu: Remove function c2h_evt_hdl()

c2h_evt_hdl() calls a dummy function rtw_hal_c2h_handler() to handle events,
so no use of keeping it.

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