drm/amd/display: Fix memleaks when atomic check fails.

While checking plane states for updates during atomic check, we create
dc_plane_states in preparation. These dc states should be freed if
something errors.

Although the input transfer function is also freed by
dc_plane_state_release(), we should free it (on error) under the same
scope as where it is created.

Signed-off-by: Leo (Sunpeng) Li <sunpeng.li@amd.com>
Reviewed-by: Harry Wentland <Harry.Wentland@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>