[MINOR] Minor fixes to exception log and removing unwanted metrics flush in integ test (#5646)

hudi-utilities/src/main/java/org/apache/hudi/utilities/deltastreamer/DeltaSync.java

@@ -846,7 +846,7 @@ public class DeltaSync implements Serializable {
       }
       return newWriteSchema;
     } catch (Exception e) {
-      throw new HoodieException("Failed to fetch schema from table.");
+      throw new HoodieException("Failed to fetch schema from table ", e);
     }
   }