watchdog: jz4740_wdt: Use 'dev' instead of dereferencing it repeatedly

Introduce local variable 'struct device *dev' and use it instead of
dereferencing it repeatedly. Also, there is no call to dev_get_drvdata()
or platform_get_drvdata() in the driver, so drop the unnecessary
call to platform_set_drvdata().

The conversion was done automatically with coccinelle using the
following semantic patches. The semantic patches and the scripts
used to generate this commit log are available at
https://github.com/groeck/coccinelle-patches



Signed-off-by: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: Wim Van Sebroeck <wim@linux-watchdog.org>