crossystem should not grumble about older firmware

Older firmware does not provide nonvolatile-context-storage FDT
property, and crossystem complains about it.

This is harmless; so just make it quiet.

Signed-off-by: Che-Liang Chiou <clchiou@chromium.org>

BRANCH=none
BUG=chrome-os-partner:14475
TEST=manual, see blow

Run crossystem and make sure its output does not contain
  "Unable to open FDT property nonvolatile-context-storage"
messages.

Check crossystem still works by comparing its output w/ and w/o this
change.

Change-Id: I0b8f40775833457a75d801f185344e931ac08847
Reviewed-on: https://gerrit.chromium.org/gerrit/33896
Commit-Ready: Che-Liang Chiou <clchiou@chromium.org>
Tested-by: Che-Liang Chiou <clchiou@chromium.org>
Reviewed-by: Simon Glass <sjg@chromium.org>
Reviewed-by: Randall Spangler <rspangler@chromium.org>
1 file changed