Fix use-of-uninitialized error in TCP.h (#43492)

`mConnectionsBuffer` cannot be accessed by TCPBase during destruction
since the derived class is destroyed first.

(cherry picked from commit 51cc1ed)

Author: dnicoara

src/transport/raw/TCP.cpp

@@ -53,11 +53,7 @@ constexpr int kListenBacklogSize = 2;
 
 } // namespace
 
-TCPBase::~TCPBase()
-{
-    // Call Close to free the listening socket and close all active connections.
-    Close();
-}
+TCPBase::~TCPBase() = default;
 
 void TCPBase::CloseActiveConnections()
 {

src/transport/raw/TCP.h

@@ -338,7 +338,13 @@ class TCP : public TCPBase
         }
     }
 
-    ~TCP() override { mPendingPackets.ReleaseAll(); }
+    ~TCP() override
+    {
+        mPendingPackets.ReleaseAll();
+
+        // Call Close to free the listening socket and close all active connections.
+        Close();
+    }
 
 private:
     ActiveTCPConnectionState mConnectionsBuffer[kActiveConnectionsSize];