[RocksJava] FlushOptions Correction

SetWaitForFlush did not set flush properly.

java/src/main/java/org/rocksdb/FlushOptions.java

@@ -24,7 +24,7 @@ public class FlushOptions extends RocksObject {
    */
   public FlushOptions setWaitForFlush(boolean waitForFlush) {
     assert(isInitialized());
-    waitForFlush(nativeHandle_);
+    setWaitForFlush(nativeHandle_, waitForFlush);
     return this;
   }