OpenBSD: wired IEEE 802.1X for OpenBSD

This is a patch for OpenBSD wired IEEE 802.1X. This is only for wired,
not wireless, because OpenBSD uses wpa_supplicant only on wired now.

http://www.openbsd.org/cgi-bin/cvsweb/ports/security/wpa_supplicant/

I have tested with these.
OS : OpenBSD 4.5
EAP : EAP-TLS
Switch : CentreCOM 8724SL

src/utils/os_unix.c

@@ -227,7 +227,8 @@ int os_setenv(const char *name, const char *value, int overwrite)
 
 int os_unsetenv(const char *name)
 {
-#if defined(__FreeBSD__) || defined(__NetBSD__) || defined(__APPLE__)
+#if defined(__FreeBSD__) || defined(__NetBSD__) || defined(__APPLE__) || \
+    defined(__OpenBSD__)
 	unsetenv(name);
 	return 0;
 #else