"rbd snap create" now reports progress. Pass --no-progress, as in
commit b5a5fea9e2 ("test/cli-integration/rbd: tweak after snap create
started to show progress").
Signed-off-by: Ilya Dryomov <idryomov@gmail.com>
Discard no longer guarantees zeroing, use BLKZEROOUT and "fallocate -z"
instead (blkdiscard(8) in xenial doesn't support -z).
Signed-off-by: Ilya Dryomov <idryomov@gmail.com>