Fix Piex ImageBuffer.createImageDataArray_ type annotation.

Fixes,

  ../../ui/file_manager/image_loader/piex_loader.js:357:
  ERROR - [JSC_UNKNOWN_EXPR_TYPE] could not determine the type of this expression
        thumbnail: this.createImageDataArray_(view, preview).buffer,
                   ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^

Bug: 1030935
Change-Id: I97a0f40f9c574e6af82aa5a46a91374db6c357f5
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2470061
Commit-Queue: Trent Apted <tapted@chromium.org>
Commit-Queue: Noel Gordon <noel@chromium.org>
Auto-Submit: Trent Apted <tapted@chromium.org>
Reviewed-by: Noel Gordon <noel@chromium.org>
Cr-Commit-Position: refs/heads/master@{#816898}

ui/file_manager/image_loader/piex_loader.js

@@ -546,7 +546,7 @@ class ImageBuffer {
    * @private
    * @param {!PiexWasmPreviewImageMetadata} preview
    * @param {!Uint8Array} view
-   * return {!Uint8Array}
+   * @return {!Uint8Array}
    */
   createImageDataArray_(view, preview) {
     const jpeg = view.byteLength > 2 && view[0] === 0xff && view[1] === 0xd8;