staging: rtl8188eu: Remove function rtw_os_indicate_scan_done()

In function rtw_indicate_scan_done, replace call to
rtw_os_indicate_scan_done with call to indicate_wx_scan_complete_event
as all that rtw_os_indicate_scan_done does is call
indicate_wx_scan_complete_event.
Remove now-unused function rtw_os_indicate_scan_done.
Issue found with Coccinelle.

Signed-off-by: Nishka Dasgupta <nishkadg.linux@gmail.com>
Link: https://lore.kernel.org/r/20190712071746.2474-4-nishkadg.linux@gmail.com


Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>