Revert "vlan: Fix VLAN 0 memory leak"

This reverts commit 718cb09a.

The commit triggers multiple syzbot issues, probably due to possibility of
manually creating VLAN 0 on netdevice which will cause the code to delete
it since it can't distinguish such VLAN from implicit VLAN 0 automatically
created for devices with NETIF_F_HW_VLAN_CTAG_FILTER feature.

Reported-by:  <syzbot+662f783a5cdf3add2719@syzkaller.appspotmail.com>
Closes: https://lore.kernel.org/all/00000000000090196d0602a6167d@google.com/


Reported-by:  <syzbot+4b4f06495414e92701d5@syzkaller.appspotmail.com>
Closes: https://lore.kernel.org/all/00000000000096ae870602a61602@google.com/


Reported-by:  <syzbot+d810d3cd45ed1848c3f7@syzkaller.appspotmail.com>
Closes: https://lore.kernel.org/all/0000000000009f0f9c0602a616ce@google.com/


Fixes: 718cb09a ("vlan: Fix VLAN 0 memory leak")
Signed-off-by: Vlad Buslov <vladbu@nvidia.com>
Reviewed-by: Ido Schimmel <idosch@nvidia.com>
Signed-off-by: David S. Miller <davem@davemloft.net>