staging: r8188eu: make OnProbeReq static

OnProbeReq is used only in rtw_mlme_ext.c. Make this function static.
Signed-off-by: Martin Kaiser <martin@kaiser.cx>
Tested-by: Philipp Hortmann <philipp.g.hortmann@gmail.com> # Edimax N150
Link: https://lore.kernel.org/r/20221024081417.66441-5-martin@kaiser.cxSigned-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/staging/r8188eu/core/rtw_mlme_ext.c

@@ -447,7 +447,7 @@ Following are the callback functions for each subtype of the management frames
 
 *****************************************************************************/
 
-unsigned int OnProbeReq(struct adapter *padapter, struct recv_frame *precv_frame)
+static unsigned int OnProbeReq(struct adapter *padapter, struct recv_frame *precv_frame)
 {
 	unsigned int	ielen;
 	unsigned char	*p;

drivers/staging/r8188eu/include/rtw_mlme_ext.h

@@ -536,8 +536,6 @@ void start_clnt_auth(struct adapter *padapter);
 void start_clnt_join(struct adapter *padapter);
 void start_create_ibss(struct adapter *padapter);
 
-unsigned int OnProbeReq(struct adapter *padapter,
-			struct recv_frame *precv_frame);
 unsigned int OnProbeRsp(struct adapter *padapter,
 			struct recv_frame *precv_frame);
 unsigned int OnBeacon(struct adapter *padapter,