[roll third_party/pigweed] SEED-0114: Claim SEED number

Original-Reviewed-on: https://pigweed-review.googlesource.com/c/pigweed/pigweed/+/175412

https://pigweed.googlesource.com/pigweed/pigweed
third_party/pigweed Rolled-Commits: c8dfc2f6700a084..e21a6c71608febe
Roller-URL: https://ci.chromium.org/b/8767586622500124801
GitWatcher: ignore
CQ-Do-Not-Cancel-Tryjobs: true
Change-Id: I4afa9b27eab756cc78793e4a2ede378edb03b1da
Reviewed-on: https://pigweed-review.googlesource.com/c/pigweed/experimental/+/175457
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 c8dfc2f..e21a6c7 160000
--- a/third_party/pigweed
+++ b/third_party/pigweed
@@ -1 +1 @@
-Subproject commit c8dfc2f6700a084cac77891aaa69a9a7dda0a369
+Subproject commit e21a6c71608febe2d4e0c4f5187ceaac78c3ba43