choose_service_tree() selects/sets both wl_class and wl_type.  Rename it to
choose_wl_class_and_type() to make it very clear.

cfq_choose_wl() only selects and sets wl_type. It is easy to confuse
it with choose_st(). So rename it to cfq_choose_wl_type() to make
it clear what does it do.

Just renaming. No functionality change.
Signed-off-by: NVivek Goyal <vgoyal@redhat.com>
Acked-by: NJeff Moyer <jmoyer@redhat.com>
Signed-off-by: NTejun Heo <tj@kernel.org>