net: sched: sch: Fix off by one in htb_activate_prios()

The > needs be >= to prevent an out of bounds access.

Fixes: de5ca4c3

 ("net: sched: sch: Bounds check priority")
Signed-off-by: Dan Carpenter <error27@gmail.com>
Reviewed-by: Simon Horman <simon.horman@corigine.com>
Reviewed-by: Kees Cook <keescook@chromium.org>
Link: https://lore.kernel.org/r/Y+D+KN18FQI2DKLq@kili
Signed-off-by: Jakub Kicinski <kuba@kernel.org>