Ip4Config2SetDnsServer may cause ASSERT if the invalid DNS server address received. The issue is triggered by the NULL pointer(Tmp) free. Cc: Ye Ting <ting.ye@intel.com> Cc: Fu Siyuan <siyuan.fu@intel.com> Contributed-under: TianoCore Contribution Agreement 1.0 Signed-off-by: Wu Jiaxin <jiaxin.wu@intel.com> Reviewed-by: Fu Siyuan <siyuan.fu@intel.com> Reviewed-by: Ye Ting <ting.ye@intel.com>