Doing so adds lots of visual clutter.

Allowing the kernel to send multiple reads for the same file handle
concurrently interferes with sequential read detection like that in
GoogleCloudPlatform/gcsfuse#103.

One of them caused the writeMessage error observed on OS X in
GoogleCloudPlatform/gcsfuse#101.

It's not expecting them.

This reproduces the writeMessage errors from
GoogleCloudPlatform/gcsfuse#101.

For GoogleCloudPlatform/gcsfuse#99.