Merge commit 'f9fe1c12' into for-next

Andreas Gruenbacher added function rhashtable_lookup_get_insert_fast
to rhashtable.h. That patch went into the net-next tree. In a
subsequent patch, GFS2 makes use of this new function. Therefore, we
needed a merge commit to make the new function available to GFS2.

Signed-off-by: Bob Peterson <rpeterso@redhat.com>