v3dv/pipeline: handle properly OUT_OF_HOST_MEMORY error when allocating p_stage

v3dv/pipeline: handle properly OUT_OF_HOST_MEMORY error when allocating p_stage

So far we were just assuming that it would work (so we could try to
access a NULL pointer), and not freeing it properly.

Fixing that was somewhat messy due pipeline_compile_graphics using a
temporary array and then update the internal pipeline stages. As we
are here we just removed the array and simplified
pipeline_compile_graphics code.

Fixes following tests:
  dEQP-VK.api.object_management.alloc_callback_fail.graphics_pipeline
  dEQP-VK.api.object_management.alloc_callback_fail_multiple.graphics_pipeline

Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/6766>