The function which handles the "Boot####", "BootOrder" ... may return failure. This patch adds the error handling codes. return the failure info to browser. Cc: Laszlo Ersek <lersek@redhat.com> Cc: Liming Gao <liming.gao@intel.com> Cc: Eric Dong <eric.dong@intel.com> Contributed-under: TianoCore Contribution Agreement 1.0 Signed-off-by: Dandan Bi <dandan.bi@intel.com> Reviewed-by: Eric Dong <eric.dong@intel.com>