change the 'r+b' to 'rb' for some file's open, since these files we only
read it and no need to write. It can fix the bug that the file's attribute
had been set to read-only.
Cc: Liming Gao <liming.gao@intel.com>
Contributed-under: TianoCore Contribution Agreement 1.0
Signed-off-by: Yonghong Zhu <yonghong.zhu@intel.com>
Reviewed-by: Liming Gao <liming.gao@intel.com>