Fix file descriptor leaks in linux CrashGenerationServer

src/client/linux/crash_generation/crash_generation_server.cc

Index: src/client/linux/crash_generation/crash_generation_server.cc
diff --git a/src/client/linux/crash_generation/crash_generation_server.cc b/src/client/linux/crash_generation/crash_generation_server.cc
index 860e8bc9f3a419bd93386b29e98df8dfdd1796b4..1d7d93b99cb4e749dafbe21c26df84f5c78ef4e9 100644
--- a/src/client/linux/crash_generation/crash_generation_server.cc
+++ b/src/client/linux/crash_generation/crash_generation_server.cc
@@ -123,6 +123,9 @@ CrashGenerationServer::Stop()
   void* dummy;
   pthread_join(thread_, &dummy);
 
+  close(control_pipe_in_);
+  close(control_pipe_out_);
+
   started_ = false;
 }