amdgpu/dm: don't use after free.

This dereference acrtc after freeing it.

Found by the kfree cocci script.
Signed-off-by: Dave Airlie <airlied@redhat.com>
Reviewed-by: Harry Wentland <harry.wentland@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>

drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c

@@ -3174,7 +3174,6 @@ int amdgpu_dm_crtc_init(struct amdgpu_display_manager *dm,
 fail:
 	kfree(acrtc);
 	kfree(cursor_plane);
-	acrtc->crtc_id = -1;
 	return res;
 }