intel: Look prime handle up in handle hash table

A slightly confused copy'n'paste from the open path where we pass in
handle but use it as a global name, in the prime handle-from-fd pass we
pass in handle and do mean handle!

References: https://bugs.freedesktop.org/show_bug.cgi?id=98416


Fixes: 2f23bf1b7b89 ("intel: Migrate handle/name lookups from linear lists...")
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>