[roll third_party/pigweed] pw_log_rpc: Test buffer is released before re-open

Test that the RpcLogDrain::server_writer_ releases the buffer before the
writer is overwritten with a new call to Open().

Original-Reviewed-on: https://pigweed-review.googlesource.com/c/pigweed/pigweed/+/72664

https://pigweed.googlesource.com/pigweed/pigweed
third_party/pigweed Rolled-Commits: 4a613e5a87149de..ed87d60b425585a
Roller-URL: https://ci.chromium.org/b/8828470426390559473
Cq-Cl-Tag: roller-builder:pigweed-sample-project-roller
Cq-Cl-Tag: roller-bid:8828470426390559473
CQ-Do-Not-Cancel-Tryjobs: true
Change-Id: I2202cd0702158e93cb36e1fd07ed94c68a67383b
Reviewed-on: https://pigweed-review.googlesource.com/c/pigweed/sample_project/+/72720
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 4a613e5..ed87d60 160000
--- a/third_party/pigweed
+++ b/third_party/pigweed
@@ -1 +1 @@
-Subproject commit 4a613e5a87149de352fcb5fe7f6ba5e5a9c161e6
+Subproject commit ed87d60b425585a8338acbe1b3abb1fe4232d448