ch-tar2dir: remove --verbose because it doesn't work

$ bin/ch-tar2dir --verbose $CH_TEST_TARDIR/chtest.tar.gz $CH_TEST_IMGDIR
creating new image /var/tmp/images/chtest
tar: invalid option -- 'y'
Try 'tar --help' or 'tar --usage' for more information.
  64KiB 0:00:00 [>                                             ]  0%

Since nobody has complained about this option not working, and it very thoroughly does not, it must not be in much demand. Let's remove it.