netdev-linux: Fix wrong ceil rate when max-rate less than 8bit.

When max-rate is less than 8bit, the hc->max_rate will be set
as htb->max_rate mistakenly instead of mtu of netdev.

Fixes: 13c1637 ("smap: New function smap_get_ullong().")
Signed-off-by: Kaige Fu <fukaige@huawei.com>
Signed-off-by: Ben Pfaff <blp@ovn.org>

lib/netdev-linux.c

@@ -3762,6 +3762,7 @@ htb_parse_class_details__(struct netdev *netdev,
 {
     const struct htb *htb = htb_get__(netdev);
     int mtu, error;
+    unsigned long long int max_rate_bit;
 
     error = netdev_linux_get_mtu__(netdev_linux_cast(netdev), &mtu);
     if (error) {
@@ -3777,10 +3778,8 @@ htb_parse_class_details__(struct netdev *netdev,
     hc->min_rate = MIN(hc->min_rate, htb->max_rate);
 
     /* max-rate */
-    hc->max_rate = smap_get_ullong(details, "max-rate", 0) / 8;
-    if (!hc->max_rate) {
-        hc->max_rate = htb->max_rate;
-    }
+    max_rate_bit = smap_get_ullong(details, "max-rate", 0);
+    hc->max_rate = max_rate_bit ? max_rate_bit / 8 : htb->max_rate;
     hc->max_rate = MAX(hc->max_rate, hc->min_rate);
     hc->max_rate = MIN(hc->max_rate, htb->max_rate);