[roll third_party/pigweed] docs: Fix typo

Original-Reviewed-on: https://pigweed-review.googlesource.com/c/pigweed/pigweed/+/173872

https://pigweed.googlesource.com/pigweed/pigweed
third_party/pigweed Rolled-Commits: bcf89442f7eb3c7..272e12409b28ca9
Roller-URL: https://ci.chromium.org/b/8768238010174935473
GitWatcher: ignore
CQ-Do-Not-Cancel-Tryjobs: true
Change-Id: I63cb69af44e3fe4df0cb6fa3be6f09334006e14f
Reviewed-on: https://pigweed-review.googlesource.com/c/pigweed/experimental/+/174038
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 bcf8944..272e124 160000
--- a/third_party/pigweed
+++ b/third_party/pigweed
@@ -1 +1 @@
-Subproject commit bcf89442f7eb3c74487fae143f380e5790f24935
+Subproject commit 272e12409b28ca93cffb469c0ad058db1f711779