[net] udp: exclude UDP_ENCAP_RXRPC packets from early demux

[Vadim Fedorenko]

On 29.01.2021 14:25, Vadim Fedorenko wrote:
> While adding the early demux for udp sockets rxrpc were not
> changed to deal with sk_rx_dst cache. That leads to leaking early
> demux cache dst reference. But adding dst_release to destructor of
> rxrpc doesn't help in situation of destroying namespace. This is
> because rxrpc does not register any netdevices per namespace.
> Assigned sk->sk_rx_dst holds the reference to netdevice preventing
> successful freeing of netdevices in namespace and moving forward to
> subsystem freeing. This is dead lock situation.
> 
> Removing rxrpc sockets from early demux util the solution in rxrpc
> subsystem is made.

Skip this please, as David Howells sent corrections to rxrpc