make our version of nla_for_each_nested() public
caputils/ws80211_utils.c contains a re-definition of the linux kernel's
nla_for_each_nested() macro that applies the correct casts to allow
compilation with a C++ compiler.
Make this definition public by moving it into a new wsutil/netlink.h
file. Include the kernel's original definition before we overwrite it. This
way, it's not necessary for a .c file to include wsutil/netlink.h after
the system includes.
Use our nla_for_each_nested() version in extcap/dpauxmon.c to squelch the
following compiler warning:
[1664/2251] Building C object
extcap/CMakeFiles/dpauxmon.dir/dpauxmon.c.o
../extcap/dpauxmon.c: In function ‘family_handler’:
../extcap/dpauxmon.c:168:13: warning: request for implicit conversion
from ‘void *’ to ‘struct nlattr *’ not permitted in C++ [-Wc++-compat]
nla_for_each_nested(mcgrp, tb[CTRL_ATTR_MCAST_GROUPS], rem_mcgrp) {
Change-Id: I6ba40ef6343c5d168c1b0c4554f13202911ded76
Reviewed-on: https://code.wireshark.org/review/27688
Reviewed-by: Anders Broman <a.broman58@gmail.com>