net: handle ARPHRD_IP6GRE in dev_is_mac_header_xmit()

net: handle ARPHRD_IP6GRE in dev_is_mac_header_xmit()

BugLink: https://bugs.launchpad.net/bugs/1947164
Similar to commit 3b707c3008ca ("net: dev_is_mac_header_xmit() true for
ARPHRD_RAWIP"), add ARPHRD_IP6GRE to dev_is_mac_header_xmit(), to make
ip6gre compatible with act_mirred and __bpf_redirect().

Signed-off-by: Guillaume Nault <gnault@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
(cherry picked from commit a3fa449ffcf5bcf9c3dddf62c11599cdc79ef54a)
Signed-off-by: Tim Gardner <tim.gardner@canonical.com>
Acked-by: Thadeu Lima de Souza Cascardo <cascardo@canonical.com>
Acked-by: Kleber Sacilotto de Souza <kleber.souza@canonical.com>
Signed-off-by: Kleber Sacilotto de Souza <kleber.souza@canonical.com>