nfc: s3fwrn5: use signed integer for parsing GPIO numbers

[ Upstream commit d8f0a86795c69f5b697f7d9e5274c124da93c92d ]

GPIOs - as returned by of_get_named_gpio() and used by the gpiolib - are
signed integers, where negative number indicates error.  The return
value of of_get_named_gpio() should not be assigned to an unsigned int
because in case of !CONFIG_GPIOLIB such number would be a valid GPIO.

Fixes: c04c674 ("nfc: s3fwrn5: Add driver for Samsung S3FWRN5 NFC Chip")
Signed-off-by: Krzysztof Kozlowski <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Jakub Kicinski <[email protected]>
Signed-off-by: Sasha Levin <[email protected]>

drivers/nfc/s3fwrn5/i2c.c

@@ -37,8 +37,8 @@ struct s3fwrn5_i2c_phy {
 	struct i2c_client *i2c_dev;
 	struct nci_dev *ndev;
 
-	unsigned int gpio_en;
-	unsigned int gpio_fw_wake;
+	int gpio_en;
+	int gpio_fw_wake;
 
 	struct mutex mutex;