radv: remove useless sync after copying query results with compute

radv: remove useless sync after copying query results with compute

The spec says:
   "vkCmdCopyQueryPoolResults is considered to be a transfer
    operation, and its writes to buffer memory must be synchronized
    using VK_PIPELINE_STAGE_TRANSFER_BIT and VK_ACCESS_TRANSFER_WRITE_BIT
    before using the results."

VK_PIPELINE_STAGE_TRANSFER_BIT will wait for compute to be idle,
while VK_ACCESS_TRANSFER_WRITE_BIT will invalidate both L1 vector
caches and L2. So, it's useless to set those flags internally.

Signed-off-by: Samuel Pitoiset <samuel.pitoiset@gmail.com>
Reviewed-by: Bas Nieuwenhuizen <bas@basnieuwenhuizen.nl>