[roll third_party/pigweed] pw_presubmit: Remove blank lines from summaries

Remove blank lines from failure summaries. These were especially
prominent in http://go/bbid/8790842636123473489.

Original-Reviewed-on: https://pigweed-review.googlesource.com/c/pigweed/pigweed/+/126997

https://pigweed.googlesource.com/pigweed/pigweed
third_party/pigweed Rolled-Commits: 1a89f09fb16460e..aaf7aa543ce96de
Roller-URL: https://ci.chromium.org/b/8790794624970604385
GitWatcher: ignore
CQ-Do-Not-Cancel-Tryjobs: true
Change-Id: I404aa40e55b4a5aeb2daa42db1c51b43fa7f37f0
Reviewed-on: https://pigweed-review.googlesource.com/c/pigweed/experimental/+/127000
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 1a89f09..aaf7aa5 160000
--- a/third_party/pigweed
+++ b/third_party/pigweed
@@ -1 +1 @@
-Subproject commit 1a89f09fb16460e27f14a16d940f2e593871fde8
+Subproject commit aaf7aa543ce96ded8b578fc337a4048ac34750ab