Make sure XENBUS interfaces are released when going into S4

Make sure XENBUS interfaces are released when going into S4

Because a transition into and out of S4 means a new domain is built, it's
crucial that all XENBUS interfaces are released (so that things like
event channels, grant tables and the xenstore ring get re-constructed).

This patch fixes code paths where this was not being done. It also adds
some more logging during AdapterEnable/Disable and when moving between
D0 and D3.

Signed-off-by: Paul Durrant <paul.durrant@citrix.com>