[roll third_party/pigweed] pw_{multisync, thread}: Enforce pw::Status return checks

Add missing pw::Status return checks to allow PW_STATUS_CFG_CHECK_IF_USED to be enabled

Original-Bug: b/247812747

Original-Reviewed-on: https://pigweed-review.googlesource.com/c/pigweed/pigweed/+/111630

https://pigweed.googlesource.com/pigweed/pigweed
third_party/pigweed Rolled-Commits: 340b0802a69431e..6d68798c659f9cc
Roller-URL: https://ci.chromium.org/b/8801841557673043297
GitWatcher: ignore
CQ-Do-Not-Cancel-Tryjobs: true
Change-Id: I4166e206be0279920df2d3c56037db960d4f5043
Reviewed-on: https://pigweed-review.googlesource.com/c/pigweed/experimental/+/112258
Commit-Queue: Pigweed Integration Roller <pigweed-integration-roller@pigweed.google.com.iam.gserviceaccount.com>
Bot-Commit: Pigweed Integration Roller <pigweed-integration-roller@pigweed.google.com.iam.gserviceaccount.com>
diff --git a/third_party/pigweed b/third_party/pigweed
index 340b080..6d68798 160000
--- a/third_party/pigweed
+++ b/third_party/pigweed
@@ -1 +1 @@
-Subproject commit 340b0802a69431e3693c07b5f54ea3253d8cd396
+Subproject commit 6d68798c659f9cc5237ec1079322792181dbbdf5