Small fix: do not replace the default CFAllocator if it has been replaced already.


git-svn-id: https://llvm.org/svn/llvm-project/compiler-rt/trunk@159824 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/asan/asan_malloc_mac.cc b/lib/asan/asan_malloc_mac.cc
index 16e9201..1626ebe 100644
--- a/lib/asan/asan_malloc_mac.cc
+++ b/lib/asan/asan_malloc_mac.cc
@@ -98,7 +98,7 @@
   CHECK(FLAG_replace_cfallocator);
   CHECK(asan_inited);
   REAL(__CFInitialize)();
-  ReplaceCFAllocator();
+  if (!cf_asan) ReplaceCFAllocator();
 }
 
 namespace {