examples: Add missing include on FreeBSD.

examples/samplesshd-tty.c

@@ -31,6 +31,9 @@ clients must be made or how a client should react.
 #ifdef HAVE_UTIL_H
 #include <util.h>
 #endif
+#ifdef HAVE_LIBUTIL_H
+#include <libutil.h>
+#endif
 #ifdef HAVE_TERMIOS_H
 #include <termios.h>
 #endif