[roll third_party/pigweed] pw_ring_buffer: Crash on corrupt buffer access

Crash when accessing a corrupt ring buffer since there is no general way
to recover and corrupt data is indicative of other major memory issues.
Remove user's expectancy of DataLoss errors and documentation in
comments and update comments where necessary.
Remove unused iterator class and status.

Original-Reviewed-on: https://pigweed-review.googlesource.com/c/pigweed/pigweed/+/59040

https://pigweed.googlesource.com/pigweed/pigweed
third_party/pigweed Rolled-Commits: c0cbc16ec823caa..478d3f2aa08f6d4
Roller-URL: https://ci.chromium.org/b/8836609225801490417
Cq-Cl-Tag: roller-builder:pigweed-sample-project-roller
Cq-Cl-Tag: roller-bid:8836609225801490417
CQ-Do-Not-Cancel-Tryjobs: true
Change-Id: I2505fec7c6318bd6d4b460b84a8045586e9d3b45
Reviewed-on: https://pigweed-review.googlesource.com/c/pigweed/sample_project/+/60300
Bot-Commit: Pigweed Integration Roller <pigweed-integration-roller@pigweed.google.com.iam.gserviceaccount.com>
Commit-Queue: Pigweed Integration Roller <pigweed-integration-roller@pigweed.google.com.iam.gserviceaccount.com>
diff --git a/third_party/pigweed b/third_party/pigweed
index c0cbc16..478d3f2 160000
--- a/third_party/pigweed
+++ b/third_party/pigweed
@@ -1 +1 @@
-Subproject commit c0cbc16ec823caa773c4d1a463dffea16240612f
+Subproject commit 478d3f2aa08f6d4c1b7167d1e949c58b64317166