radeon/video: always use the reusable buffer pool

radeon/video: always use the reusable buffer pool

A semantic error was introduced in a past refactoring that caused the bind
parameter to be passed into the use_reusable_pool parameter of buffer_create.
Since this clearly makes no sense, and there is no clear reason why the
cache _shouldn't_ be used, just use the cache always.

Cc: Christian König <christian.koenig@amd.com>
Reviewed-by: Christian König <christian.koenig@amd.com>
Reviewed-by: Marek Olšák <marek.olsak@amd.com>