Fix minor typo in java comments (#867)

Author: haoch

driver-core/src/main/com/mongodb/connection/Stream.java

@@ -101,7 +101,7 @@ default ByteBuf read(int numBytes, int additionalTimeout) throws IOException {
      * callback on completion.
      *
      * @param buffers the buffers to write
-     * @param handler invoked when the read operation has completed
+     * @param handler invoked when the write operation has completed
      */
     void writeAsync(List<ByteBuf> buffers, AsyncCompletionHandler<Void> handler);