net_ocsp: Explicitly ignore result of CalledOnValidThread().

net/ocsp/nss_ocsp.cc

Index: net/ocsp/nss_ocsp.cc
diff --git a/net/ocsp/nss_ocsp.cc b/net/ocsp/nss_ocsp.cc
index d83b239f8c59e6157ded51ec8c67adbcf742b460..4a4b8f670aef5c78579a3fdffb4780130127da9e 100644
--- a/net/ocsp/nss_ocsp.cc
+++ b/net/ocsp/nss_ocsp.cc
@@ -88,7 +88,10 @@ class OCSPIOLoop {
       base::AutoLock autolock(lock_);
       DCHECK(base::MessageLoopForIO::current());
       thread_checker_.DetachFromThread();
-      thread_checker_.CalledOnValidThread();
+
+      // CalledOnValidThread is the only available API to reassociate
+      // thread_checker_ with the current thread. Result ignored intentionally.
+      ignore_result(thread_checker_.CalledOnValidThread());
       shutdown_ = false;
       used_ = false;
     }