refcache: Use a better hash function
refcache: Use a better hash function

This is still a lame hash function, but it uses more bits of the
pointer, so at least it doesn't leave 93.75% of the hash table unused
because of page_info's alignment.

aclements/sv6,bowlofstew/sv6,aclements/sv6,bowlofstew/sv6,aclements/sv6,bowlofstew/sv6,aclements/sv6,bowlofstew/sv6,aclements/sv6,bowlofstew/sv6