qcacmn: Properly validate QCA_WLAN_VENDOR_ATTR_NDP_IFACE_STR

Currently the QCA_WLAN_VENDOR_ATTR_NDP_IFACE_STR nla_policy specifies
a type of NLA_STRING, but the underlying implementation expects a
NUL-terminated string. Update the policy to correctly use a type of
NLA_NUL_STRING with the len updated to remove the allocation needed
for the terminating NUL.

Change-Id: Ic73241511ab73ae63fd7c1a8d6422da91931919c
CRs-Fixed: 2063588

os_if/linux/nan/src/os_if_nan.c

@@ -38,8 +38,8 @@ static const struct nla_policy
 vendor_attr_policy[QCA_WLAN_VENDOR_ATTR_NDP_PARAMS_MAX + 1] = {
 	[QCA_WLAN_VENDOR_ATTR_NDP_SUBCMD] = { .type = NLA_U32 },
 	[QCA_WLAN_VENDOR_ATTR_NDP_TRANSACTION_ID] = { .type = NLA_U16 },
-	[QCA_WLAN_VENDOR_ATTR_NDP_IFACE_STR] = { .type = NLA_STRING,
-					.len = IFNAMSIZ },
+	[QCA_WLAN_VENDOR_ATTR_NDP_IFACE_STR] = { .type = NLA_NUL_STRING,
+					.len = IFNAMSIZ - 1 },
 	[QCA_WLAN_VENDOR_ATTR_NDP_SERVICE_INSTANCE_ID] = { .type = NLA_U32 },
 	[QCA_WLAN_VENDOR_ATTR_NDP_CHANNEL] = { .type = NLA_U32 },
 	[QCA_WLAN_VENDOR_ATTR_NDP_PEER_DISCOVERY_MAC_ADDR] = {