roll: third_party/pigweed c91d97a..fd8bb48 (2 commits)

fd8bb48:https://pigweed-review.googlesource.com/c/pigweed/pigweed/+/382832 pw_async2: Do not hold the lock during Wake()
f0ac35a:https://pigweed-review.googlesource.com/c/pigweed/pigweed/+/386812 pw_allocator: Assert ok result in Init()

Rolled-Repo: https://pigweed.googlesource.com/pigweed/pigweed
Rolled-Commits: c91d97a6e21e15..fd8bb48ea3d365
Roll-Count: 1
Roller-URL: https://cr-buildbucket.appspot.com/build/8687124218163224161
GitWatcher: ignore
CQ-Do-Not-Cancel-Tryjobs: true
Change-Id: Ic2fed97917e5beaaa96ea80996bdba87d169a44d
Reviewed-on: https://pigweed-review.googlesource.com/c/pigweed/examples/+/386872
diff --git a/third_party/pigweed b/third_party/pigweed
index c91d97a..fd8bb48 160000
--- a/third_party/pigweed
+++ b/third_party/pigweed
@@ -1 +1 @@
-Subproject commit c91d97a6e21e15c2908838652d4ba0ac00af03fd
+Subproject commit fd8bb48ea3d3655c5fa1b1adfc4f8fcb29f5951b