iproute2 renamed the configure script output file to config.mk. Update
the config tweaking code accordingly.
The configure script now detects xtables correctly, drop this part.
Add a comment to explain the TC_CONFIG_XT disable tweak.
Cc: Petr Vorel <petr.vorel@gmail.com>
Signed-off-by: Baruch Siach <baruch@tkos.co.il>
Acked-by: Petr Vorel <petr.vorel@gmail.com>
Signed-off-by: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>
f822cd793b