Merge branch 'report-erspan-version-field-just-for-erspan-tunnels'

Lorenzo Bianconi says:

====================
report erspan version field just for erspan tunnels

Do not report erspan_version to userpsace for non erspan tunnels.
Report IFLA_GRE_ERSPAN_INDEX only for erspan version 1 in
ip6gre_fill_info
====================

Signed-off-by: David S. Miller <davem@davemloft.net>