add new errno testes for timerfd_*

* Add EINVAL errno testes for timerfd_create(2)
	- The clockid argument is neither CLOCK_MONOTONIC nor CLOCK_REALTIME,
	  EINVAL would return.
	- flags is invalid, EINVAL would return.

* Add EBADF, EFAULT and EINVAL errno testes for timerfd_gettime(2)
	- fd is not a valid file descriptor, EBADF would return.
	- curr_value is not valid a pointer, EFAULT would return.
	- fd is not a valid timerfd file descriptor, EINVAL would return.

* Add EBADF, EFAULT and EINVAL errno testes for timerfd_settime(2)
	- fd is not a valid file descriptor, EBADF would return.
	- old_value is not valid a pointer, EFAULT would return.
	- fd is not a valid timerfd file descriptor, EINVAL would return.
	- flags is invalid, EINVAL would return.

Signed-off-by: Zeng Linggang <zenglg.jy@cn.fujitsu.com>
Tested-by: Jan Stancek <jstancek@redhat.com>