staging: r8188eu: don't call empty DoReserved function

Replace the DoReserved function pointer with NULL in mlme_sta_tbl. We can
skip the function call for reserved subtypes.
Signed-off-by: Martin Kaiser <martin@kaiser.cx>
Link: https://lore.kernel.org/r/20220417102221.466524-6-martin@kaiser.cxSigned-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/staging/r8188eu/core/rtw_mlme_ext.c

@@ -22,8 +22,8 @@ static mlme_handler mlme_sta_tbl[] = {
 	OnAssocRsp,
 	OnProbeReq,
 	OnProbeRsp,
-	DoReserved,
-	DoReserved,
+	NULL,
+	NULL,
 	OnBeacon,
 	OnAtim,
 	OnDisassoc,