pw_system: Reword log stream error message

Change-Id: If52b5b362c5773ac591a14dc96bcd5450e6a7907
Reviewed-on: https://pigweed-review.googlesource.com/c/pigweed/pigweed/+/74940
Pigweed-Auto-Submit: Carlos Chinchilla <cachinchilla@google.com>
Reviewed-by: Armando Montanez <amontanez@google.com>
Commit-Queue: Auto-Submit <auto-submit@pigweed.google.com.iam.gserviceaccount.com>
diff --git a/pw_system/init.cc b/pw_system/init.cc
index cc0f5f9..6ca411f 100644
--- a/pw_system/init.cc
+++ b/pw_system/init.cc
@@ -33,7 +33,8 @@
   const Status status = GetLogThread().OpenUnrequestedLogStream(
       kDefaultChannelId, GetRpcServer(), GetLogService());
   if (!status.ok()) {
-    PW_LOG_ERROR("Error opening OpenUnrequestedLogStream %s", status.str());
+    PW_LOG_ERROR("Error opening unrequested log streams %d",
+                 static_cast<int>(status.code()));
   }
 
   PW_LOG_INFO("Registering RPC services");