Time profiler: small fixes and optimizations

Summary: Fixes from Roman's review here: https://reviews.llvm.org/D58675#1465336

Reviewers: lebedev.ri

Subscribers: hiraditya, mgrang, cfe-commits, llvm-commits

Tags: #clang, #llvm

Differential Revision: https://reviews.llvm.org/D60663

llvm-svn: 358448
diff --git a/clang/tools/driver/cc1_main.cpp b/clang/tools/driver/cc1_main.cpp
index 337c7d7..ae60fefd 100644
--- a/clang/tools/driver/cc1_main.cpp
+++ b/clang/tools/driver/cc1_main.cpp
@@ -239,7 +239,7 @@
                                 /*Extension=*/"json",
                                 /*useTemporary=*/false);
 
-    llvm::timeTraceProfilerWrite(profilerOutput);
+    llvm::timeTraceProfilerWrite(*profilerOutput);
     llvm::timeTraceProfilerCleanup();
   }