watchdog: digicolor_wdt: Remove unused variable in dc_wdt_probe

clang warns:

drivers/watchdog/digicolor_wdt.c:121:6: warning: unused variable 'ret'
[-Wunused-variable]
int ret;
^
1 warning generated.

It's unused now, remove it.

Fixes: cdad26977e3f ("watchdog: digicolor_wdt: drop warning after registering device")
Link: https://github.com/ClangBuiltLinux/linux/issues/591
Reported-by: kernelci.org bot <[e-mail]>
Signed-off-by: Nathan Chancellor <[e-mail]>
Reviewed-by: Guenter Roeck <[e-mail]>
Link: https://lore.kernel.org/r/[e-mail]
Signed-off-by: Guenter Roeck <[e-mail]>
Signed-off-by: Wim Van Sebroeck <[e-mail]>

drivers/watchdog/digicolor_wdt.c

···
 {
 	struct device *dev = &pdev->dev;
 	struct dc_wdt *wdt;
-	int ret;
 
 	wdt = devm_kzalloc(dev, sizeof(struct dc_wdt), GFP_KERNEL);
 	if (!wdt)