drm/radeon: use pointers instead of indexes for CS chunks

Nobody is interested at which index the chunk is. What's needed is
a pointer to the chunk. Remove unused chunk_id field as well.

Signed-off-by: Christian König <christian.koenig@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
diff --git a/drivers/gpu/drm/radeon/radeon_trace.h b/drivers/gpu/drm/radeon/radeon_trace.h
index 9db74a9..ce075cb 100644
--- a/drivers/gpu/drm/radeon/radeon_trace.h
+++ b/drivers/gpu/drm/radeon/radeon_trace.h
@@ -38,7 +38,7 @@
 
 	    TP_fast_assign(
 			   __entry->ring = p->ring;
-			   __entry->dw = p->chunks[p->chunk_ib_idx].length_dw;
+			   __entry->dw = p->chunk_ib->length_dw;
 			   __entry->fences = radeon_fence_count_emitted(
 				p->rdev, p->ring);
 			   ),