Fix uninitialized command Length variable in TPM1.2 Self Test command Contributed-under: TianoCore Contribution Agreement 1.0 Signed-off-by: Samer El-Haj-Mahmoud <elhaj@hpe.com> Signed-off-by: Derek Lin <derek.lin2@hpe.com> Reviewed-by: Chao Zhang <chao.b.zhang@intel.com> Reviewed-by: Yao Jiewen <jiewen.yao@intel.com>