nfc: constify passed nfc_dev

The struct nfc_dev is not modified by nfc_get_drvdata() and
nfc_device_name() so it can be made a const.
Signed-off-by: NKrzysztof Kozlowski <krzysztof.kozlowski@canonical.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

include/net/nfc/nfc.h

@@ -245,7 +245,7 @@ static inline void nfc_set_drvdata(struct nfc_dev *dev, void *data)
  *
  * @dev: The nfc device
  */
-static inline void *nfc_get_drvdata(struct nfc_dev *dev)
+static inline void *nfc_get_drvdata(const struct nfc_dev *dev)
 {
 	return dev_get_drvdata(&dev->dev);
 }
@@ -255,7 +255,7 @@ static inline void *nfc_get_drvdata(struct nfc_dev *dev)
  *
  * @dev: The nfc device whose name to return
  */
-static inline const char *nfc_device_name(struct nfc_dev *dev)
+static inline const char *nfc_device_name(const struct nfc_dev *dev)
 {
 	return dev_name(&dev->dev);
 }