Fix treesit-search-forward

Fix treesit-search-forward

Move the check for movement

    (if (> arg 0)
        ;; Make sure we moved forward.
        (> (funcall pos-fn node) starting-point)
      ;; Make sure we moved backward.
      (< (funcall pos-fn node) starting-point))

into cl-loop:

    if (treesit-node-eq cap-node node)

becomes

    if (and (treesit-node-eq cap-node node)
            (if (> arg 0)
                ;; Make sure we moved forward.
                (> (funcall pos-fn node)
                   starting-point)
              ;; Make sure we moved backward.
              (< (funcall pos-fn node)
                 starting-point)))

* lisp/treesit.el (treesit-search-forward): Move the check.