err is set once, then first code resets it.
  err = tcf_exts_validate(...)
Signed-off-by: NStephen Hemminger <stephen@networkplumber.org>
Acked-by: NJamal Hadi Salim <hadi@mojatatu.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>