drm/amd/display: Release state memory if amdgpu_dm_create_color_properties fail

[Why]
Coverity reports RESOURCE_LEAK warning. State memory
is not released if dm_create_color_properties fail.

[How]
Call kfree(state) before return.

Reviewed-by: Alex Hung <alex.hung@amd.com>
Reviewed-by: Harry Wentland <harry.wentland@amd.com>
Acked-by: Tom Chung <chiahsuan.chung@amd.com>
Signed-off-by: Hersen Wu <hersenxs.wu@amd.com>
Tested-by: Daniel Wheeler <daniel.wheeler@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>