[orchagent] Fix: ERR swss#orchagent: :- setPortPvid: pvid setting for tunnel Port_EVPN_XXX is not allowed (sonic-net#3402)

* Fix: ERR swss#orchagent: :- setPortPvid: pvid setting for tunnel Port_EVPN_XXX is not allowed

Tunnel ports are always tagged and can't be created as untagged.  But
the code currently tries to set a pvid on a tunnel which is disallowed
leading to an error in the logs.

This is a simple fix to get rid of the error in the logs.  It
does not actually change behavior in any way other than getting rid
of an error thus helping debugability.

Author: bradh352

orchagent/portsorch.cpp

@@ -6500,7 +6500,8 @@ bool PortsOrch::addVlanMember(Port &vlan, Port &port, string &tagging_mode, stri
             port.m_alias.c_str(), vlan.m_alias.c_str(), vlan.m_vlan_info.vlan_id, port.m_port_id);
 
     /* Use untagged VLAN as pvid of the member port */
-    if (sai_tagging_mode == SAI_VLAN_TAGGING_MODE_UNTAGGED)
+    if (sai_tagging_mode == SAI_VLAN_TAGGING_MODE_UNTAGGED &&
+        port.m_type != Port::TUNNEL)
     {
         if(!setPortPvid(port, vlan.m_vlan_info.vlan_id))
         {
@@ -6835,7 +6836,8 @@ bool PortsOrch::removeVlanMember(Port &vlan, Port &port, string end_point_ip)
             port.m_alias.c_str(), vlan.m_alias.c_str(), vlan.m_vlan_info.vlan_id, vlan_member_id);
 
     /* Restore to default pvid if this port joined this VLAN in untagged mode previously */
-    if (sai_tagging_mode == SAI_VLAN_TAGGING_MODE_UNTAGGED)
+    if (sai_tagging_mode == SAI_VLAN_TAGGING_MODE_UNTAGGED &&
+        port.m_type != Port::TUNNEL)
     {
         if (!setPortPvid(port, DEFAULT_PORT_VLAN_ID))
         {

orchagent/vxlanorch.cpp

@@ -2409,8 +2409,8 @@ bool EvpnRemoteVnip2pOrch::addOperation(const Request& request)
     }
 
     // SAI Call to add tunnel to the VLAN flood domain
-
-    string tagging_mode = "untagged"; 
+    // NOTE: does 'untagged' make the most sense here?
+    string tagging_mode = "untagged";
     gPortsOrch->addVlanMember(vlanPort, tunnelPort, tagging_mode);
 
     SWSS_LOG_INFO("remote_vtep=%s vni=%d vlanid=%d ",
@@ -2569,7 +2569,7 @@ bool EvpnRemoteVnip2mpOrch::addOperation(const Request& request)
     }
 
     // SAI Call to add tunnel to the VLAN flood domain
-
+    // NOTE: does 'untagged' make the most sense here?
     string tagging_mode = "untagged";
     gPortsOrch->addVlanMember(vlanPort, tunnelPort, tagging_mode, end_point_ip);