packet: pdiag_put_ring() should return TX_RING info for TPACKET_V3

Commit 7f953ab2 ("af_packet: TX_RING support for TPACKET_V3")
now makes it possible to use TX_RING with TPACKET_V3, so make the
the relevant information available via 'ss -e -a --packet'

Signed-off-by: Sowmini Varadhan <sowmini.varadhan@oracle.com>
Signed-off-by: David S. Miller <davem@davemloft.net>