[Msan] Fix the DynRet unit test to build on FreeBSD

Differential Revision: http://reviews.llvm.org/D7086

llvm-svn: 226799

compiler-rt/lib/msan/tests/msan_test.cc

@@ -511,10 +511,9 @@ static char *DynRetTestStr;
 
 TEST(MemorySanitizer, DynRet) {
   ReturnPoisoned<S8>();
-  EXPECT_NOT_POISONED(clearenv());
+  EXPECT_NOT_POISONED(atoi("0"));
 }
 
-
 TEST(MemorySanitizer, DynRet1) {
   ReturnPoisoned<S8>();
 }