Merge branch 'net-sched-cls-add-extack-support'

Alexander Aring says:

====================
net: sched: cls: add extack support

this patch adds extack support for TC classifier subsystem. The first
patch fixes some code style issues for this patch series pointed out
by checkpatch. The other patches until the last one prepares extack
handling for the TC classifier subsystem and handle generic extack
errors.

The last patch is an example for u32 classifier to add extack support
inside the callbacks delete and change. There exists a init callback as
well, but most classifier implementation run a kalloc() once to allocate
something. Not necessary _yet_ to add extack support now.

- Alex

Cc: David Ahern <dsahern@gmail.com>
changes since v3:
 - fix accidentally move of config option mismatch message in PATCH 2/8
   correct one is 4/8, detected by kbuildbot (Thank you)
 - Removed patch "net: sched: cls: add extack support for tc_setup_cb_call"
   PATCH 7/8 in version v2 as suggested by Jakub Kicinski (Thank you)
 - changed NL_SET_ERR_MSG to NL_SET_ERR_MSG_MOD as suggested by Jakub Kicinski
   in u32 cls (Thank You)
 - Removed text from cover letter that I was waiting for Jiri's Patches as
   detected by Jamal Hadi Salim (Thank you).

changes since v2:
 - rebased on Jiri's patches (Thank you)
 - several spelling fixes pointed out by Cong Wang (Thank you)
 - several spelling fixes pointed out by David Ahern (Thank you)
 - use David Ahern recommendation if config option is mismatch, but
   combine it with Cong Wang recommendation to put config name into it
   (Thank you)
====================

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