radv: Don't use both DCC and CMASK for single sample images.

Fixes: c67ef7695a2 "radv: Use ac_surface to allocate aux surfaces."
Reviewed-by: Samuel Pitoiset <samuel.pitoiset@gmail.com>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/6194>
diff --git a/src/amd/vulkan/radv_image.c b/src/amd/vulkan/radv_image.c
index 4644393..343a5d8 100644
--- a/src/amd/vulkan/radv_image.c
+++ b/src/amd/vulkan/radv_image.c
@@ -1233,9 +1233,11 @@
 radv_image_alloc_single_sample_cmask(const struct radv_image *image,
                                      struct radeon_surf *surf)
 {
+	assert(image->info.storage_samples == 1 || surf->cmask_offset);
+
 	if (!surf->cmask_size || surf->cmask_offset || surf->bpe > 8 ||
 	    image->info.levels > 1 || image->info.depth > 1 ||
-	    !radv_image_use_fast_clear_for_image(image))
+	    radv_image_has_dcc(image) || !radv_image_use_fast_clear_for_image(image))
 		return;
 
 	surf->cmask_offset = align64(surf->total_size, surf->cmask_alignment);