Fix _BSD_SOURCE/__USE_BSD.

Bug: 14659579
Change-Id: I80ec9584f054c02d1078828f6bca759c42bc1d4c
diff --git a/libc/upstream-openbsd/android/include/openbsd-compat.h b/libc/upstream-openbsd/android/include/openbsd-compat.h
index 34ad2c5..488b5f9 100644
--- a/libc/upstream-openbsd/android/include/openbsd-compat.h
+++ b/libc/upstream-openbsd/android/include/openbsd-compat.h
@@ -17,11 +17,11 @@
 #ifndef _BIONIC_OPENBSD_COMPAT_H_included
 #define _BIONIC_OPENBSD_COMPAT_H_included
 
+#define _BSD_SOURCE
+
 #include <sys/cdefs.h>
 #include <stddef.h> // For size_t.
 
-#define __USE_BSD
-
 /* OpenBSD's <ctype.h> uses these names, which conflicted with stlport.
  * Additionally, we changed the numeric/digit type from N to D for libcxx.
  */