net: hns: fix uninitialized data use

When dev_dbg() is enabled, we print uninitialized data, as gcc-7.0.1
now points out:

ethernet/hisilicon/hns/hns_dsaf_main.c: In function 'hns_dsaf_set_promisc_tcam':
ethernet/hisilicon/hns/hns_dsaf_main.c:2947:75: error: 'tbl_tcam_data.low.val' may be used uninitialized in this function [-Werror=maybe-uninitialized]
ethernet/hisilicon/hns/hns_dsaf_main.c:2947:75: error: 'tbl_tcam_data.high.val' may be used uninitialized in this function [-Werror=maybe-uninitialized]

We also pass the data into hns_dsaf_tcam_mc_cfg(), which might later
use it (not sure about that), so it seems safer to just always initialize
the tbl_tcam_data structure.

Fixes: 1f5fa2dd ("net: hns: fix for promisc mode in HNS driver")
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: David S. Miller <davem@davemloft.net>

drivers/net/ethernet/hisilicon/hns/hns_dsaf_main.c

@@ -2924,10 +2924,11 @@ void hns_dsaf_set_promisc_tcam(struct dsaf_device *dsaf_dev,
 	/* find the tcam entry index for promisc */
 	entry_index = dsaf_promisc_tcam_entry(port);
 
-	/* config key mask */
-	if (enable) {
 	memset(&tbl_tcam_data, 0, sizeof(tbl_tcam_data));
 	memset(&tbl_tcam_mask, 0, sizeof(tbl_tcam_mask));
+
+	/* config key mask */
+	if (enable) {
 		dsaf_set_field(tbl_tcam_data.low.bits.port_vlan,
 			       DSAF_TBL_TCAM_KEY_PORT_M,
 			       DSAF_TBL_TCAM_KEY_PORT_S, port);