ASAN: Use after scope in conformance_concurrent_queue

concurrent_queue_rep holds reference to Allocator, which is managed by
concurrent_queue. This reference can be invalid after moving
concurrent_queue_rep from one concurrent_queue to another.

Updating concurrent_queue_rep for using provider Allocator instead of
holding reference.

Signed-off-by: Serov, Vladimir <vladimir.serov@intel.com>