radv: plug leaks in radv_device_init_accel_struct_build_state
I was having issues completing a full CTS run on a 4GB device due to leaks. For example, dEQP-VK.image.swapchain_mutable.x*
leaked several hundreds of MBs due to this.
I assume the internal nir shaders can be safely freed after the pipelines are created. Let me know if it is not the case.
Fixes: 0dad88b4 ("radv: Implement device-side BVH building.")