net: bridge: fix a possible memory leak in __vlan_add

net: bridge: fix a possible memory leak in __vlan_add

After per-port vlan stats, vlan stats should be released
when fail to add vlan

Fixes: 9163a0fc1f0c0 ("net: bridge: add support for per-port vlan stats")
CC: [email protected]
cc: Nikolay Aleksandrov <[email protected]>
CC: Roopa Prabhu <[email protected]>
Signed-off-by: Zhang Yu <[email protected]>
Signed-off-by: Li RongQing <[email protected]>
Signed-off-by: Nikolay Aleksandrov <[email protected]>
Signed-off-by: David S. Miller <[email protected]>