ovs: disable StartLimitBurst in the ovs-cleanup service

With systemd 255, the ovs integration test is hitting this limit and the
test fails due to that. As it's a oneshot service, it should be OK to
disable this limit.

src/openvswitch.c

@@ -60,6 +60,11 @@ write_ovs_systemd_unit(const char* id, const GString* cmds, const char* rootdir,
     }
 
     g_string_append(s, "\n[Service]\nType=oneshot\nTimeoutStartSec=10s\n");
+    /* During tests the rate in which the netplan-ovs-cleanup service is started/stopped
+     * might exceed StartLimitBurst.
+     */
+    if (cleanup)
+        g_string_append(s, "StartLimitBurst=0\n");
     g_string_append(s, cmds->str);
 
     g_string_free_to_file(s, rootdir, path, NULL);

tests/generator/base.py

@@ -70,7 +70,7 @@
 OVS_BR_EMPTY = _OVS_BASE + 'After=netplan-ovs-cleanup.service\nBefore=network.target\nWants=network.target\n\n[Service]\n\
 Type=oneshot\nTimeoutStartSec=10s\nExecStart=/usr/bin/ovs-vsctl --may-exist add-br %(iface)s\n' + OVS_BR_DEFAULT
 OVS_CLEANUP = _OVS_BASE + 'ConditionFileIsExecutable=/usr/bin/ovs-vsctl\nBefore=network.target\nWants=network.target\n\n\
-[Service]\nType=oneshot\nTimeoutStartSec=10s\nExecStart=/usr/sbin/netplan apply --only-ovs-cleanup\n'
+[Service]\nType=oneshot\nTimeoutStartSec=10s\nStartLimitBurst=0\nExecStart=/usr/sbin/netplan apply --only-ovs-cleanup\n'
 UDEV_MAC_RULE = 'SUBSYSTEM=="net", ACTION=="add", DRIVERS=="%s", ATTR{address}=="%s", NAME="%s"\n'
 UDEV_NO_MAC_RULE = 'SUBSYSTEM=="net", ACTION=="add", DRIVERS=="%s", NAME="%s"\n'
 UDEV_SRIOV_RULE = 'ACTION=="add", SUBSYSTEM=="net", ATTRS{sriov_totalvfs}=="?*", RUN+="/usr/sbin/netplan apply --sriov-only"\n'