docker-storage-setup: Skip block zeroing in thin pool
docker-storage-setup: Skip block zeroing in thin pool

By default docker sets up a thin pool where block zeroing is skipped. This
script basically sets up a pool for docker, so use same behavior.

In general thin pool folks have recommended using skip block zeroing. 

Signed-off-by: Vivek Goyal <61d11262d0d9873ddb5a887f48fcb04e8c5973d0@redhat.com>

shishir-a412ed/docker-storage-setup,thescriptbender/container-storage-setup