timerfd: Remove an always true check

We would have returned -EINVAL earlier if ticks wasn't set.

Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Cc: Alexander Viro <viro@zeniv.linux.org.uk>
Cc: Cyrill Gorcunov <gorcunov@openvz.org>
Link: http://lkml.kernel.org/r/20140801082848.GF28869@mwanda


Signed-off-by: Thomas Gleixner <tglx@linutronix.de>