mei: move read cb to complete queue if not connected

Move read cb to the completion queue if a read finds out that client
is not connected. This expedite user space reader wake on error
condition.

Signed-off-by: Alexander Usyskin <alexander.usyskin@intel.com>
Signed-off-by: Tomas Winkler <tomas.winkler@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>