test_msg(): avoid recursion

In (highly unlikely) case localtime() failed, test_msg() calls
pr_perror() which is a wrapper around test_msg() so we're
calling ourselves, which can lead to infinite recursion if
localtime() keeps failing. Use fprintf() here to avoid this.

Signed-off-by: Kir Kolyshkin <kir@openvz.org>
Acked-by: Andrew Vagin <avagin@gmail.com>
Signed-off-by: Pavel Emelyanov <xemul@parallels.com>