[Misc] Fixed compilation failure with gcc 7.4

Summary: Fixed build failure caused by -Werror=format-security

Test Plan: build and sanity test

Reviewed-by: D-D-H, mmyxym

Issue: https://github.com/alibaba/dragonwell8/issues/79

src/share/vm/gc_implementation/g1/elasticHeap.cpp

@@ -290,7 +290,7 @@ Monitor*    ElasticHeapTimer::_monitor = NULL;
 
 bool ElasticHeapTimer::has_error(TRAPS, const char* error) {
   if (HAS_PENDING_EXCEPTION) {
-    tty->print_cr(error);
+    tty->print_cr("%s", error);
     java_lang_Throwable::print(PENDING_EXCEPTION, tty);
     tty->cr();
     CLEAR_PENDING_EXCEPTION;

src/share/vm/jfr/periodic/jfrThreadCPULoadEvent.cpp

@@ -127,7 +127,7 @@ void JfrThreadCPULoadEvent::send_events() {
     }
     jt = jt->next();
   }
-  log_trace(jfr)("Measured CPU usage for %d threads in %.3f milliseconds", thread_count,
+  log_trace(jfr)("Measured CPU usage for " SIZE_FORMAT " threads in %.3f milliseconds", thread_count,
     (double)(JfrTraceTime::now() - event_time) / (JfrTraceTime::frequency() / 1000));
   // Restore this thread's thread id
   periodic_trace_data->set_thread_id(periodic_thread_id);

src/share/vm/jfr/utilities/jfrJavaLog.cpp

@@ -44,19 +44,19 @@ void JfrJavaLog::log(jint tag_set, jint level, jstring message, TRAPS) {
   case LogLevel::Off:
     break;
   case LogLevel::Trace:
-    log_trace(jfr)(s);
+    log_trace(jfr)("%s", s);
     break;
   case LogLevel::Debug:
-    log_debug(jfr)(s);
+    log_debug(jfr)("%s", s);
     break;
   case LogLevel::Info:
-    log_info(jfr)(s);
+    log_info(jfr)("%s", s);
     break;
   case LogLevel::Warning:
-    log_warning(jfr)(s);
+    log_warning(jfr)("%s", s);
     break;
   case LogLevel::Error:
-    log_error(jfr)(s);
+    log_error(jfr)("%s", s);
     break;
   default:
     break;