test: make TEST-60-MOUNT-RATELIMIT more robust

TEST-60-MOUNT-RATELIMIT sometimes fails as it cannot see the 'left rate limit'
message in the journal. Tests relying on specific log messages are often flaky,
as the journal is lossy.
Change the test case to check for the desired outcome instead, as that also
catches regressions, without being over reliant on the journal.

Fixes https://github.com/systemd/systemd/issues/32712

test/units/TEST-60-MOUNT-RATELIMIT.sh

@@ -159,13 +159,15 @@ testcase_mount_ratelimit() {
     # If the infra is slow we might not enter the rate limit state; in that case skip the exit check.
     journalctl --sync
     if timeout 2m bash -c "journalctl -u init.scope --since='$ts' -n all --follow | grep -m 1 -q -F '(mount-monitor-dispatch) entered rate limit'"; then
-        journalctl --sync
-        timeout 2m bash -c "journalctl -u init.scope --since='$ts' -n all --follow | grep -m 1 -q -F '(mount-monitor-dispatch) left rate limit'"
+        # We entered the rate limit state. Verify that the manager leaves it again on its own and
+        # processes the pending mount table changes, i.e. that all the mount units we unmounted above are
+        # cleaned up automatically, without daemon-reload.
+        timeout 2m bash -c 'while systemctl list-units -t mount tmp-meow* | grep tmp-meow >/dev/null; do sleep 1; done'
+    else
+        # We never entered the rate limit state (e.g. on slow infra), so the recovery path above is not
+        # being exercised. Just make sure the mount units are cleaned up, nudging the manager if needed.
+        timeout 2m bash -c 'while systemctl list-units -t mount tmp-meow* | grep tmp-meow >/dev/null; do systemctl daemon-reload; sleep 10; done'
     fi
-
-    # Verify that the mount units are always cleaned up at the end.
-    # Give some time for units to settle so we don't race between exiting the rate limit state and cleaning up the units.
-    timeout 2m bash -c 'while systemctl list-units -t mount tmp-meow* | grep tmp-meow >/dev/null; do systemctl daemon-reload; sleep 10; done'
 }
 
 mkdir -p /run/systemd/journald.conf.d