Revert "ipvlan: properly track tx_errors"

This reverts commit af50165c which is
commit ff672b9f upstream.

It breaks the ABI, so it must be removed at this point in time.  If it
is needed in the future, it can be brought back in an abi-safe way.

Bug: 161946584
Change-Id: Ide21bf33d413133a412f9455a7000acc1e22a148
Signed-off-by: Greg Kroah-Hartman <gregkh@google.com>