Snapshot reservation sync calls wrong resource.

The snapshot reservations code isn't calling the
correct resource on sync (it's calling volumes).  There's
also some problems with the logic being used on the delete/clean up
that are fixed here as well.

Fixes bug: 1157506
Fixes bug: 1157982

Change-Id: I91327b8043ab63aa35ea8a91b6de544bf5bf6c61
(cherry picked from commit b450eef832ff471b78776c9715b0878e95d69263)
Merge "Snapshot reservation sync calls wrong resource." into milestone-proposed