net: sched: using TCQ_MIN_PRIO_BANDS in prio_tune()

Using TCQ_MIN_PRIO_BANDS instead of magic number in prio_tune().

Signed-off-by: Zhengchao Shao <shaozhengchao@huawei.com>
Acked-by: Cong Wang <xiyou.wangcong@gmail.com>
Link: https://lore.kernel.org/r/20220826041035.80129-1-shaozhengchao@huawei.com


Signed-off-by: Paolo Abeni <pabeni@redhat.com>