Use model_query() in db.*****_destroy

Use model_query() in db.*****_destroy

Use model_query() instead of session.query in db.volume_destroy,
db.volume_type_destroy, db.transfer_destroy and db.snapshot_destroy as
other methods use.
model_query function is the query helper which is used in most part of
cinder/db/sqlalchemy/api.py.

Change-Id: I97be252df9d40bb97231e3341d5cedec26af2d93
Closes-Bug: #1256483