mei: handle tx queue flushing for vtag connections

mei: handle tx queue flushing for vtag connections

Since multiple file pointers (fp) can be associated
with a single host client, upon close() only objects
associated with the fp has to flushed from the tx queues.
The control queues should be flushed only when all
the connections are closed and the client is disconnected.

Signed-off-by: Alexander Usyskin <alexander.usyskin@intel.com>
Signed-off-by: Tomas Winkler <tomas.winkler@intel.com>
Link: https://lore.kernel.org/r/20200818115147.2567012-9-tomas.winkler@intel.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>