set_lsb_release: enable batch modification

When setting a field, this script mounts the image, unmounts, mounts
it, then writes the field, then unmounts it.  When setting 4 or 5
keys at once, this is quite a waste.

Tweak it so we only mount it once, and we can set multiple keys in
a single call by looping over the input args.

BUG=None
TEST=`./signing_unittests.py` passes
BRANCH=None

Change-Id: Id7dc4e8ef58113cc4632721851fcab04ef1e69eb
Reviewed-on: https://gerrit.chromium.org/gerrit/42601
Reviewed-by: Ryan Cui <rcui@chromium.org>
Commit-Queue: Mike Frysinger <vapier@chromium.org>
Tested-by: Mike Frysinger <vapier@chromium.org>

0 files changed, 0 insertions, 0 deletions