Fix variable for $chef_installer in omnibus-chef.install echo statement.
Bump omnibus-chef to 11.16.2:
 - use chef-container-11.16.2 release
 - consolidate some prepare() msgs
 - ensure no already built makeself installers exist in srcdir
 - use --without development instead of --binstubs with bundle install
 - do a bundle show for debug log level
 - change to support new .run makeself isntaller extension (was .sh)