YARN-11240. Fix incorrect placeholder in yarn-module.

Author: slfan1989

hadoop-yarn-project/hadoop-yarn/hadoop-yarn-applications/hadoop-yarn-services/hadoop-yarn-services-core/src/main/java/org/apache/hadoop/yarn/service/ServiceScheduler.java

@@ -1139,7 +1139,7 @@ public void syncSysFs(Service yarnApp) {
         LOG.info("YARN sysfs synchronized.");
       }
     } catch (IOException | URISyntaxException | InterruptedException e) {
-      LOG.error("Fail to sync service spec: {}", e);
+      LOG.error("Fail to sync service spec: {}", e.getMessage());
     }
   }
 }

hadoop-yarn-project/hadoop-yarn/hadoop-yarn-applications/hadoop-yarn-services/hadoop-yarn-services-core/src/test/java/org/apache/hadoop/yarn/service/TestServiceAM.java

@@ -553,7 +553,7 @@ public void testSyncSysFS() {
       am.stop();
       am.close();
     } catch (Exception e) {
-      LOG.error("Fail to sync sysfs: {}", e);
+      LOG.error("Fail to sync sysfs: {}", e.getMessage());
       Assert.fail("Fail to sync sysfs.");
     }
   }