[roll third_party/pigweed] docs: Prefer rvalue references

Original-Reviewed-on: https://pigweed-review.googlesource.com/c/pigweed/pigweed/+/193647

https://pigweed.googlesource.com/pigweed/pigweed
third_party/pigweed Rolled-Commits: 55dcce2af4ea7e5..2423b1d51274848
Roller-URL: https://ci.chromium.org/b/8754988489195016081
GitWatcher: ignore
CQ-Do-Not-Cancel-Tryjobs: true
Change-Id: I6f28193c657502f162dd591d20654411df74347c
Reviewed-on: https://pigweed-review.googlesource.com/c/pigweed/experimental/+/194192
Bot-Commit: Pigweed Roller <pigweed-roller@pigweed-service-accounts.iam.gserviceaccount.com>
Commit-Queue: Pigweed Roller <pigweed-roller@pigweed-service-accounts.iam.gserviceaccount.com>
diff --git a/third_party/pigweed b/third_party/pigweed
index 55dcce2..2423b1d 160000
--- a/third_party/pigweed
+++ b/third_party/pigweed
@@ -1 +1 @@
-Subproject commit 55dcce2af4ea7e533aa15e20ea4e5aa0b3320e1c
+Subproject commit 2423b1d5127484848e036d6626524fba3156bf43