libvndksupport: Do not lookup default namespace for sphal failure

Instead of looking up default namespace for the failure of loading
sphal libs, report failure. This is only for the devices that have
sphal namespace.

Bug: 38435840
Test: sailfish builds and boots
Test: libvndksupport-tests passes
Change-Id: Ibbff5f2d5d83f6482f98677a5492777db6416967