sch_tbf: use do_div() for 64-bit divide

It's doing a 64-bit divide which is not supported
on 32-bit architectures in psched_ns_t2l(). The
correct way to do this is to use do_div().

It's introduced by commit cc106e44
("net: sched: tbf: fix the calculation of max_size")
Reported-by: kbuild test robot <fengguang.wu@intel.com>
Signed-off-by: Yang Yingliang <yangyingliang@huawei.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

net/sched/sch_tbf.c

@@ -131,8 +131,10 @@ static u64 psched_ns_t2l(const struct psched_ratecfg *r,
 
 	do_div(len, NSEC_PER_SEC);
 
-	if (unlikely(r->linklayer == TC_LINKLAYER_ATM))
-		len = (len / 53) * 48;
+	if (unlikely(r->linklayer == TC_LINKLAYER_ATM)) {
+		do_div(len, 53);
+		len = len * 48;
+	}
 
 	if (len > r->overhead)
 		len -= r->overhead;