watchdog: xen_wdt: remove info message and version number

The initial info message (early in the xen_wdt_init_module() function)
is not very useful and we already have a message on successful probe. If
the probe fails, additional messages are printed anyway.

The version number serves no useful purpose and it ran out of favor
upstream anyway.

Signed-off-by: Radu Rendec <rrendec@arista.com>
Reviewed-by: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: Wim Van Sebroeck <wim@iguana.be>