drm/amdgpu: Use allowed_domains for pinning dmabufs

When determining the domains for pinning DMABufs, filter allowed_domains
and fail with a warning if VRAM is forbidden and GTT is not an allowed
domain.

Fixes: f5e7fabd1f5c ("drm/amdgpu: allow pinning DMA-bufs into VRAM if all importers can do P2P")
Suggested-by: Christian König <[e-mail]>
Signed-off-by: Felix Kuehling <[e-mail]>
Reviewed-by: Christian König <[e-mail]>
Signed-off-by: Alex Deucher <[e-mail]>

drivers/gpu/drm/amd/amdgpu/amdgpu_dma_buf.c

···
 {
 	struct dma_buf *dmabuf = attach->dmabuf;
 	struct amdgpu_bo *bo = gem_to_amdgpu_bo(dmabuf->priv);
-	u32 domains = bo->preferred_domains;
+	u32 domains = bo->allowed_domains;
 
 	dma_resv_assert_held(dmabuf->resv);
 
···
 
 	if (domains & AMDGPU_GEM_DOMAIN_VRAM)
 		bo->flags |= AMDGPU_GEM_CREATE_CPU_ACCESS_REQUIRED;
+
+	if (WARN_ON(!domains))
+		return -EINVAL;
 
 	return amdgpu_bo_pin(bo, domains);
 }