system-kmod-macros: Load modern nf_conntrack modules.

Modules were renamed around kernel 4.18.  New name doesn't have the
protocol version.  Also, we need to load the netlink module to have
access to conntrack dumps.

While these modules are likely to always be present and not actually
be unloadable due to being in use by many different things in the
system, they may not be loaded in minimalistic environments like
virtme-ng.  And tests fail without them.

Same change was merged into OVS recently.

Signed-off-by: Ilya Maximets <i.maximets@ovn.org>
Signed-off-by: Ales Musil <amusil@redhat.com>
(cherry picked from commit 8eccb22)

Author: igsilya

tests/system-kmod-macros.at

@@ -63,8 +63,13 @@ m4_define([CONFIGURE_VETH_OFFLOADS],
 # Perform requirements checks for running conntrack tests, and flush the
 # kernel conntrack tables when the test is finished.
 #
+# nf_conntrack_ipv[46] are old names in kernels before 4.18.  These will
+# fail on newer kernels, while nf_conntrack will fail on older ones.  But
+# these failures do not affect the test execution.
+#
 m4_define([CHECK_CONNTRACK],
-     m4_foreach([mod], [[nf_conntrack_ipv4], [nf_conntrack_ipv6]],
+     m4_foreach([mod], [[nf_conntrack_ipv4], [nf_conntrack_ipv6],
+                        [nf_conntrack], [nf_conntrack_netlink]],
                 [modprobe mod && on_exit 'modprobe -r mod' || echo "Module mod not loaded."
                 ])
      sysctl -w net.netfilter.nf_conntrack_helper=0