selftests: tc: add ConnTrack procfs kconfig

When looking at the TC selftest reports, I noticed one test was failing
because /proc/net/nf_conntrack was not available.

  not ok 373 3992 - Add ct action triggering DNAT tuple conflict
  	Could not match regex pattern. Verify command output:
  cat: /proc/net/nf_conntrack: No such file or directory

It is only available if NF_CONNTRACK_PROCFS kconfig is set. So the issue
can be fixed simply by adding it to the list of required kconfig.

Fixes: e469056 ("tc-testing: add test for ct DNAT tuple collision")
Cc: [email protected]
Link: https://lore.kernel.org/netdev/[email protected]/T/ [1]
Signed-off-by: Matthieu Baerts <[email protected]>
Tested-by: Zhengchao Shao <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Acked-by: Jamal Hadi Salim <[email protected]>
Signed-off-by: Jakub Kicinski <[email protected]>

Author: matttbe

tools/testing/selftests/tc-testing/config

@@ -5,6 +5,7 @@ CONFIG_NF_CONNTRACK=m
 CONFIG_NF_CONNTRACK_MARK=y
 CONFIG_NF_CONNTRACK_ZONES=y
 CONFIG_NF_CONNTRACK_LABELS=y
+CONFIG_NF_CONNTRACK_PROCFS=y
 CONFIG_NF_FLOW_TABLE=m
 CONFIG_NF_NAT=m
 CONFIG_NETFILTER_XT_TARGET_LOG=m