habanalabs: verify that kernel CB is destroyed only once

Remove the distinction between user CB and kernel CB, and verify for
both that they are not destroyed more than once.

As kernel CB might be taken from the pre-allocated CB pool, so we need
to clear the handle destroyed indication when returning a CB to the
pool.

Signed-off-by: Tomer Tayar <ttayar@habana.ai>
Reviewed-by: Oded Gabbay <ogabbay@kernel.org>
Signed-off-by: Oded Gabbay <ogabbay@kernel.org>