xen-evtchn: correct comment and error output

The evtchn device has been moved to /dev/xen. Also change log level to
KERN_ERR as other xen drivers.

Signed-off-by: Wei Liu <wei.liu2@citrix.com>
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
1 file changed