selftests/net: enable msg_zerocopy test

The existing msg_zerocopy test takes additional protocol arguments.
Add a variant that takes no arguments and runs all supported variants.
Call this from kselftest.

Signed-off-by: Willem de Bruijn <willemb@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2 files changed