intel-mid_wdt: Error code is just an integer

Error code when printed is more readable if it's represented as plain decimal
integer. Otherwise user will see something like
	intel_mid_wdt: Error stopping watchdog: 0xffffffed
which is not quite understandable ("Should I interpret it as a bitfield?").

Make it clear to use plaint integer specifier.

While here, move struct device *dev local variable definition to the top of
functions.

Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Reviewed-by: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: Guenter Roeck <linux@roeck-us.net>