iio: dac: stm32-dac: Use pm_runtime_resume_and_get() to replace open coding.

Found using coccicheck script under review at:
https://lore.kernel.org/lkml/[e-mail]/

This is a prequel to taking a closer look at the runtime pm in IIO drivers
in general

Signed-off-by: Jonathan Cameron <[e-mail]>
Cc: Fabrice Gasnier <[e-mail]>
Reviewed-by: Fabrice Gasnier <[e-mail]>
Reviewed-by: Mauro Carvalho Chehab <[e-mail]>
Link: https://lore.kernel.org/r/[e-mail]

drivers/iio/dac/stm32-dac.c

···
 	}
 
 	if (enable) {
-		ret = pm_runtime_get_sync(dev);
+		ret = pm_runtime_resume_and_get(dev);
 		if (ret < 0) {
-			pm_runtime_put_noidle(dev);
 			mutex_unlock(&dac->lock);
 			return ret;
 		}