Enforce driver is initialized

This updates the volume manager and the
backup manager to enforce that the driver
has been initialized.

The managers call the driver in many places
without ensuring that the driver has been
properly initialized.   When the driver fails
inside of do_setup(), the managers shouldn't
call the driver's set_initialized() method.
The managers now dump out the exception, and
exit the init_host, leaving the driver in
an uninitialized state.

Fixes bug #1225897

Change-Id: I77b947f2a9fbe1b38f321511dba10fcd2fe1fe90
Merge "Enforce driver is initialized"