Eliminate need to resolve cache based on the queue. This allows to share
the queue between cache instances. The queue still holds pointer to
a cache that owns the queue, but no management or io path relies on the
queue -> cache mapping.
Signed-off-by: Robert Baldyga <robert.baldyga@huawei.com>
Signed-off-by: Michal Mielewczyk <michal.mielewczyk@huawei.com>