[roll third_party/pigweed] pw_rpc: Cancel and reinvoke duplicate calls

If ongoing RPC is called again, the server cancels the current call and
reinvokes the RPC. Previously, a duplicate reader/writer object would be
created, which would be given to the user to handle. This enforces a
consistent policy for all RPCs.

Original-Reviewed-on: https://pigweed-review.googlesource.com/c/pigweed/pigweed/+/56243

https://pigweed.googlesource.com/pigweed/pigweed
third_party/pigweed Rolled-Commits: 38ef479133f0e9d..85e914071b2857c
Roller-URL: https://ci.chromium.org/b/8839346948438825793
Cq-Cl-Tag: roller-builder:pigweed-experimental-roller
Cq-Cl-Tag: roller-bid:8839346948438825793
CQ-Do-Not-Cancel-Tryjobs: true
Change-Id: I7eb5c40affd3d076f231a2208b9dc7cdcf975985
Reviewed-on: https://pigweed-review.googlesource.com/c/pigweed/experimental/+/56546
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 38ef479..85e9140 160000
--- a/third_party/pigweed
+++ b/third_party/pigweed
@@ -1 +1 @@
-Subproject commit 38ef479133f0e9de3eb35e2abe8fb5bc45d48264
+Subproject commit 85e914071b2857c4139313b01571d994bd0fbeb9