anv: when handling descriptor sets, layout cannot be NULL if dynamic_offets are used

We have no cases where we intentionally pass a NULL layout when dynamic
offsets, and doing so would cause a null dereference. Le't asd an assert
for that.

CID: 1620447
Fixes: f39cd30f4f ("anv: Track all the descriptor sets")
Reviewed-by: Lionel Landwerlin <lionel.g.landwerlin@intel.com>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/31638>

src/intel/vulkan/anv_cmd_buffer.c

@@ -875,6 +875,7 @@ anv_cmd_buffer_bind_descriptor_set(struct anv_cmd_buffer *cmd_buffer,
    if (dynamic_offsets) {
       if (set_layout->dynamic_offset_count > 0) {
          struct anv_push_constants *push = &pipe_state->push_constants;
+         assert(layout != NULL);
          uint32_t dynamic_offset_start =
             layout->set[set_index].dynamic_offset_start;
          uint32_t *push_offsets =