Remove D (pinned) from CWP perf commands on CPU cycles.

The "D" qualifier was introduced in https://chromium-review.googlesource.com/c/chromium/src/+/2649429.

However, it is not necessary and adding it needs separate discussion.

Bug: b:175448047
Change-Id: I962bd43834ae86ab49d3d05dea071924a554cdee
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2653318


Reviewed-by: Gabriel Marin <gmx@chromium.org>
Commit-Queue: Bin Du <dubin@google.com>
Cr-Commit-Position: refs/heads/master@{#848168}