mfd: arizona: Check errors from regcache_sync()

If the control bus is unrelabile we may hit errors during regcache_sync(),
especially given that it tends to be one the most dense bursts of I/O in
many systems.
Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>
Signed-off-by: Samuel Ortiz <sameo@linux.intel.com>

drivers/mfd/arizona-core.c

@@ -239,7 +239,12 @@ static int arizona_runtime_resume(struct device *dev)
 		return ret;
 	}
 
-	regcache_sync(arizona->regmap);
+	ret = regcache_sync(arizona->regmap);
+	if (ret != 0) {
+		dev_err(arizona->dev, "Failed to restore register cache\n");
+		regulator_disable(arizona->dcvdd);
+		return ret;
+	}
 
 	return 0;
 }