Code clean up in NetLib:

1. Add GLOBAL_REMOVE_IF_UNREFERENCED to all globals
2. Update NTOHL and NTOHS to be BaseLib func SwapBytes32/SwapBytes16
3. Remove duplicate NET_SWAP_SHORT (to use NTOHS instead)

git-svn-id: https://edk2.svn.sourceforge.net/svnroot/edk2/trunk/edk2@9648 6f19259b-4bc3-4df7-8a09-765794883524

MdeModulePkg/Universal/Network/Tcp4Dxe/Tcp4Input.c

@@ -799,7 +799,7 @@ TcpInput (
       Tcb     = TcpCloneTcb (Parent);
       if (Tcb == NULL) {
         DEBUG ((EFI_D_ERROR, "TcpInput: discard a segment because"
-          "failed to clone a child for TCB%x\n", Tcb));
+          " failed to clone a child for TCB%x\n", Tcb));
 
         goto DISCARD;
       }