Merge branch 'act_gate-fixes'

Davide Caratti says:

====================
two fixes for 'act_gate' control plane

- patch 1/2 attempts to fix the error path of tcf_gate_init() when users
  try to configure 'act_gate' rules with wrong parameters
- patch 2/2 is a follow-up of a recent fix for NULL dereference in
  the error path of tcf_gate_init()

further work will introduce a tdc test for 'act_gate'.

changes since v2:
  - fix undefined behavior in patch 1/2
  - improve comment in patch 2/2
changes since v1:
  coding style fixes in patch 1/2 and 2/2
====================

Signed-off-by: David S. Miller <davem@davemloft.net>