DuetPkg: Use 'echo off' in BATCH script files

DuetPkg: Use 'echo off' in BATCH script files

Instead of putting a '@' at the beginning of every command in BATCH script
files, use 'echo off' at the beginning of each file.

Cc: Ruiyu Ni <ruiyu.ni@intel.com>
Contributed-under: TianoCore Contribution Agreement 1.0
Signed-off-by: Hao Wu <hao.a.wu@intel.com>
Reviewed-by: Ruiyu Ni <ruiyu.ni@intel.com>