net: allow dumping of gre0 and gretap0
net: allow dumping of gre0 and gretap0

These devices are injected into every network namespace when the ip_gre
module is loaded. They cannot be configured as usable tunnels, so let's
just ignore them.

Signed-off-by: Tycho Andersen <10c18fcb898ee6b17d6575d444b125d10b3f4d6a@canonical.com>
Signed-off-by: Pavel Emelyanov <c9a32589e048e044184536f7ac71ef92fe82df3e@virtuozzo.com>

eabatalov/criu,KKoukiou/criu-remote,efiop/criu,efiop/criu,efiop/criu,AuthenticEshkinKot/criu,AuthenticEshkinKot/criu,eabatalov/criu,AuthenticEshkinKot/criu,eabatalov/criu,KKoukiou/criu-remote,AuthenticEshkinKot/criu,eabatalov/criu,KKoukiou/criu-remote,eabatalov/criu,KKoukiou/criu-remote,AuthenticEshkinKot/criu,efiop/criu,efiop/criu,KKoukiou/criu-remote,AuthenticEshkinKot/criu,efiop/criu,eabatalov/criu,KKoukiou/criu-remote