staging: rtl8723bs: core: Remove wrapper functions

Remove function power_saving_wk_hdl as all it does is call
rtw_ps_processor. Edit call sites accordingly.
Remove function reset_securitypriv_hdl as all it does is call
rtw_reset_securitypriv. Modify call sites accordingly.
Remove function free_assoc_resources_hdl as all it does is call
rtw_free_assoc_resources with one extra constant argument, and the
former is only called once.
Issue found with Coccinelle.

Signed-off-by: Nishka Dasgupta <nishkadg.linux@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>