Fix NetBSD 32-bit build
Replace 'defined(SANITIZER_OPENBSD)' with appropriate 'SANITIZER_OPENBSD'.
This is a fallout from adding OpenBSD partial support.
@@ -172,7 +172,7 @@ typedef u64 OFF64_T;
#if (SANITIZER_WORDSIZE == 64) || SANITIZER_MAC
typedef uptr operator_new_size_type;
#else
-# if defined(SANITIZER_OPENBSD) || defined(__s390__) && !defined(__s390x__)
+# if SANITIZER_OPENBSD || defined(__s390__) && !defined(__s390x__)
// Special case: 31-bit s390 has unsigned long as size_t.
typedef unsigned long operator_new_size_type;
# else
