profiling: Make rule_perf.log JSON output newline-delimited

Adding a newline makes the output valid JSON when multiple sortings of
the rules profile object are written to the log.

src/util-profiling-rules.c

@@ -340,7 +340,7 @@ static void DumpJson(FILE *fp, SCProfileSummary *summary,
 
     if (unlikely(js_s == NULL))
         return;
-    fprintf(fp, "%s", js_s);
+    fprintf(fp, "%s\n", js_s);
     free(js_s);
     json_decref(js);
 }