1.Fix a bug in Dhcp4Dxe driver to correct the ‘secs’ field in DHCP message.

Signed-off-by: sfu5
Reviewed-by: tye
Reviewed-by: xdu2

git-svn-id: https://edk2.svn.sourceforge.net/svnroot/edk2/trunk/edk2@12742 6f19259b-4bc3-4df7-8a09-765794883524

MdeModulePkg/Universal/Network/Dhcp4Dxe/Dhcp4Driver.c

@@ -478,6 +478,7 @@ DhcpInitProtocol (
   Instance->RenewRebindEvent  = NULL;
   Instance->Token             = NULL;
   Instance->UdpIo             = NULL;
+  Instance->ElaspedTime       = 0;
   NetbufQueInit (&Instance->ResponseQueue);
 }