platform/chrome: cros_ec_sysfs: introduce to_cros_ec_dev define.

Add a define to get the cros_ec_dev from device and use it.
Suggested-by: NAndy Shevchenko <andy.shevchenko@gmail.com>
Signed-off-by: NEnric Balletbo i Serra <enric.balletbo@collabora.com>
Reviewed-by: NAndy Shevchenko <andy.shevchenko@gmail.com>
Signed-off-by: NBenson Leung <bleung@chromium.org>

drivers/platform/chrome/cros_ec_sysfs.c

@@ -34,6 +34,8 @@
 #include <linux/types.h>
 #include <linux/uaccess.h>
 
+#define to_cros_ec_dev(dev)  container_of(dev, struct cros_ec_dev, class_dev)
+
 /* Accessor functions */
 
 static ssize_t show_ec_reboot(struct device *dev,
@@ -70,8 +72,7 @@ static ssize_t store_ec_reboot(struct device *dev,
 	int got_cmd = 0, offset = 0;
 	int i;
 	int ret;
-	struct cros_ec_dev *ec = container_of(dev,
-					      struct cros_ec_dev, class_dev);
+	struct cros_ec_dev *ec = to_cros_ec_dev(dev);
 
 	msg = kmalloc(sizeof(*msg) + sizeof(*param), GFP_KERNEL);
 	if (!msg)
@@ -132,8 +133,7 @@ static ssize_t show_ec_version(struct device *dev,
 	struct cros_ec_command *msg;
 	int ret;
 	int count = 0;
-	struct cros_ec_dev *ec = container_of(dev,
-					      struct cros_ec_dev, class_dev);
+	struct cros_ec_dev *ec = to_cros_ec_dev(dev);
 
 	msg = kmalloc(sizeof(*msg) + EC_HOST_PARAM_SIZE, GFP_KERNEL);
 	if (!msg)
@@ -231,8 +231,7 @@ static ssize_t show_ec_flashinfo(struct device *dev,
 	struct ec_response_flash_info *resp;
 	struct cros_ec_command *msg;
 	int ret;
-	struct cros_ec_dev *ec = container_of(dev,
-					      struct cros_ec_dev, class_dev);
+	struct cros_ec_dev *ec = to_cros_ec_dev(dev);
 
 	msg = kmalloc(sizeof(*msg) + sizeof(*resp), GFP_KERNEL);
 	if (!msg)