drm/amd/display: handle failed allocation during stream construction

[Why]
Failing to allocate a transfer function during stream construction leads
to a null pointer dereference

[How]
Handle the failed allocation by failing the stream construction

Cc: stable@vger.kernel.org
Signed-off-by: Josip Pavic <Josip.Pavic@amd.com>
Reviewed-by: Aric Cyr <Aric.Cyr@amd.com>
Acked-by: Rodrigo Siqueira <Rodrigo.Siqueira@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>