staging: rtl8188eu: remove dummy setfreq handler

The setfreq handler contains only a debug print. It returns success
although the frequency wasn't set.

Remove this handler and inform callers that this driver does not
support setfreq.
Signed-off-by: Martin Kaiser <martin@kaiser.cx>
Link: https://lore.kernel.org/r/20210529121346.8422-3-martin@kaiser.cxSigned-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/staging/rtl8188eu/os_dep/ioctl_linux.c

@@ -667,14 +667,6 @@ static int rtw_wx_get_name(struct net_device *dev,
 	return 0;
 }
 
-static int rtw_wx_set_freq(struct net_device *dev,
-			   struct iw_request_info *info,
-			   union iwreq_data *wrqu, char *extra)
-{
-	RT_TRACE(_module_rtl871x_mlme_c_, _drv_notice_, ("+%s\n", __func__));
-	return 0;
-}
-
 static int rtw_wx_get_freq(struct net_device *dev,
 			   struct iw_request_info *info,
 			   union iwreq_data *wrqu, char *extra)
@@ -2894,7 +2886,6 @@ static int rtw_wx_set_priv(struct net_device *dev,
 
 static iw_handler rtw_handlers[] = {
 	IW_HANDLER(SIOCGIWNAME, rtw_wx_get_name),
-	IW_HANDLER(SIOCSIWFREQ, rtw_wx_set_freq),
 	IW_HANDLER(SIOCGIWFREQ, rtw_wx_get_freq),
 	IW_HANDLER(SIOCSIWMODE, rtw_wx_set_mode),
 	IW_HANDLER(SIOCGIWMODE, rtw_wx_get_mode),