Split dlerror() logging statement in generate_stubs.py

We are seeing cases where dlerror() crashes without a known reason
under MSAN in a logging statement of InitializeStubs() during
PulseAudio initialization.
This CL splits the logging statement that reports the library that
failed to open and the call to dlerror().
This will allow us to see in the logs which library failed to load prior
to the dlerror crash.


Bug: 1109346
Change-Id: I3adbdf27e7207404a0c4d8a9fd472b77a8932c8b
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2332259
Commit-Queue: Nico Weber <thakis@chromium.org>
Auto-Submit: Guido Urdaneta <guidou@chromium.org>
Reviewed-by: Nico Weber <thakis@chromium.org>
Cr-Commit-Position: refs/heads/master@{#794845}

tools/generate_stubs/generate_stubs.py

@@ -311,8 +311,8 @@ UMBRELLA_INITIALIZER_INITIALIZE_FUNCTION_START = (
         module_opened = true;
         opened_libraries[cur_module] = handle;
       } else {
-        %(logging_function)s << "dlopen(" << dso_path->c_str() << ") failed, "
-                << "dlerror() says:\\n" << dlerror();
+        %(logging_function)s << "dlopen(" << dso_path->c_str() << ") failed.";
+        %(logging_function)s << "dlerror() says:\\n" << dlerror();
       }
     }