cgpt: do not show length of 1 for undefined partitions

If a partition isn't "defined", then don't declare its size as 1.

BUG=chromium:236941
TEST=`cbuildbot {x86,amd64,arm}-generic-full` pass
TEST=`cgpt show -i 100 -s chromiumos_image.bin` shows 0
BRANCH=none

Change-Id: I538546b6b37a9137958d6f926a58753cf52c946a
Reviewed-on: https://gerrit.chromium.org/gerrit/50074
Reviewed-by: Bill Richardson <wfrichar@chromium.org>
Commit-Queue: Mike Frysinger <vapier@chromium.org>
Tested-by: Mike Frysinger <vapier@chromium.org>
1 file changed