net: dsa: b53: fix an off by one in checking "vlan->vid"

commit 8e4052c upstream.

The > comparison should be >= to prevent accessing one element beyond
the end of the dev->vlans[] array in the caller function, b53_vlan_add().
The "dev->vlans" array is allocated in the b53_switch_init() function
and it has "dev->num_vlans" elements.

Fixes: a2482d2 ("net: dsa: b53: Plug in VLAN support")
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Acked-by: Florian Fainelli <f.fainelli@gmail.com>
Link: https://lore.kernel.org/r/YAbxI97Dl/pmBy5V@mwanda
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/net/dsa/b53/b53_common.c

@@ -1142,7 +1142,7 @@ int b53_vlan_prepare(struct dsa_switch *ds, int port,
 	if ((is5325(dev) || is5365(dev)) && vlan->vid_begin == 0)
 		return -EOPNOTSUPP;
 
-	if (vlan->vid_end > dev->num_vlans)
+	if (vlan->vid_end >= dev->num_vlans)
 		return -ERANGE;
 
 	b53_enable_vlan(dev, true, dev->vlan_filtering_enabled);