Drivers: hv: vmbus: Fix a rescind handling bug

Drivers: hv: vmbus: Fix a rescind handling bug

BugLink: http://bugs.launchpad.net/bugs/1672544
commit ccb61f8a99e6c29df4fb96a65dad4fad740d5be9 upstream.

The host can rescind a channel that has been offered to the
guest and once the channel is rescinded, the host does not
respond to any requests on that channel. Deal with the case where
the guest may be blocked waiting for a response from the host.

Signed-off-by: K. Y. Srinivasan <kys@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Tim Gardner <tim.gardner@canonical.com>