libplugin: make leaks log at LOG_BROKEN so they break CI.

Now we've fixed them, this makes sure CI notices if new leaks appear.

Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>

plugins/libplugin.c

@@ -1182,8 +1182,7 @@ static void PRINTF_FMT(1,2) log_memleak(const char *fmt, ...)
 	va_list ap;
 
 	va_start(ap, fmt);
-	/* FIXME: This is LOG_DEBUG until we fix leaks! */
-	plugin_logv(memleak_plugin, LOG_DEBUG, fmt, ap);
+	plugin_logv(memleak_plugin, LOG_BROKEN, fmt, ap);
 	va_end(ap);
 }