Fix a bug in DHCP6 driver when using DUID LLT.
Fix a bug in DHCP6 driver when using DUID LLT.

Contributed-under: TianoCore Contribution Agreement 1.0
Signed-off-by: Fu Siyuan <siyuan.fu@intel.com>
Reviewed-by: Dong Eric <eric.dong@intel.com>
Reviewed-by: Wu Jiaxin <jiaxin.wu@intel.com>

git-svn-id: 3158a46dfd52e07d1fda3e32e1ab2e353a00b20f@16337 6f19259b-4bc3-4df7-8a09-765794883524

MattDevo/edk2,MattDevo/edk2,MattDevo/edk2,MattDevo/edk2,MattDevo/edk2,MattDevo/edk2,MattDevo/edk2,MattDevo/edk2