ibmveth: Fix use of ibmveth in a bridge.

ibmveth: Fix use of ibmveth in a bridge.

[ Upstream commit 2ac8af0967aaa2b67cb382727e784900d2f4d0da ]

The check for src mac address in ibmveth_is_packet_unsupported is wrong.
Commit 6f2275433a2f wanted to shut down messages for loopback packets,
but now suppresses bridged frames, which are accepted by the hypervisor
otherwise bridging won't work at all.

Fixes: 6f2275433a2f ("ibmveth: Detect unsupported packets before sending to the hypervisor")
Signed-off-by: Michal Suchanek <msuchanek@suse.de>
Signed-off-by: Thomas Bogendoerfer <tbogendoerfer@suse.de>
Link: https://lore.kernel.org/r/20201026104221.26570-1-msuchanek@suse.de
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>