Walking a linear list to find a matching PRIME handle or flinked name
does not scale and becomes a major burden with just a few objects.
That said, the fixed size hash is not much better, it just buckets the
look into a few separate chains rather than one long one.
References: https://bugs.freedesktop.org/show_bug.cgi?id=94631
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>