devmapper fix usage of pool transaction id 

Fixes Issue: #9257

There are multiple issues with current devmapper usage of pool transaction Id. This patch series tries to fix these.

Details of problem and proposed fix are available in Issue: #9257

Thanks
Vivek
Why is this closeTransaction call here?
It seems from the commit history that it is paired with the openTransaction in deleteDevice(), but i don't understand how that would work.