drm/amd/display: prevent memory leak

In dcn*_create_resource_pool the allocated memory should be released if
construct pool fails.

Reviewed-by: Harry Wentland <harry.wentland@amd.com>
Signed-off-by: Navid Emamdoost <navid.emamdoost@gmail.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>