dev_install: catch people who run `sudo su`

We need the full environment from a login shell.  Barf if we don't.

BUG=None
TEST=`sudo dev_install` works
TEST=`sudo su -; dev_install` works
TEST=`sudo su; dev_install` aborts

Change-Id: I96647c342f6f47dc5657ad8688b7ee784fd3054d
Reviewed-on: https://gerrit.chromium.org/gerrit/59111
Reviewed-by: Ronald G. Minnich <rminnich@chromium.org>
Tested-by: Mike Frysinger <vapier@chromium.org>
Commit-Queue: Mike Frysinger <vapier@chromium.org>
1 file changed