Handle an invalid IPv6 address in NetLibAsciiStrToIp6(), like '2000:aaaa::1com'. Cc: Zhang Lubo <lubo.zhang@intel.com> Cc: Fu Siyuan <siyuan.fu@intel.com> Cc: Ye Ting <ting.ye@intel.com> Contributed-under: TianoCore Contribution Agreement 1.0 Signed-off-by: Jiaxin Wu <jiaxin.wu@intel.com> Reviewed-by: Fu Siyuan <siyuan.fu@intel.com> Reviewed-by: Zhang Lubo <lubo.zhang@intel.com>