Disable recursive interception for tzset in MSan

This fixes sanitization of this library call on NetBSD.
Extracted as a part of D42050.

llvm-svn: 346098

compiler-rt/lib/msan/msan_interceptors.cc

@@ -1072,6 +1072,7 @@ extern char *tzname[2];
 
 INTERCEPTOR(void, tzset, int fake) {
   ENSURE_MSAN_INITED();
+  InterceptorScope interceptor_scope;
   REAL(tzset)(fake);
   if (tzname[0])
     __msan_unpoison(tzname[0], REAL(strlen)(tzname[0]) + 1);