leds: pca955x: Correct I2C Functionality

The driver checks an incorrect flag of functionality of adapter.
When a driver requires i2c_smbus_read_byte_data and
i2c_smbus_write_byte_data, it should check I2C_FUNC_SMBUS_BYTE_DATA
instead I2C_FUNC_I2C.
This patch fixes the problem.

Signed-off-by: Tin Huynh <tnhuynh@apm.com>
Signed-off-by: Jacek Anaszewski <jacek.anaszewski@gmail.com>
diff --git a/drivers/leds/leds-pca955x.c b/drivers/leds/leds-pca955x.c
index 78a7ce8..9a87311 100644
--- a/drivers/leds/leds-pca955x.c
+++ b/drivers/leds/leds-pca955x.c
@@ -285,7 +285,7 @@ static int pca955x_probe(struct i2c_client *client,
 			"slave address 0x%02x\n",
 			client->name, chip->bits, client->addr);
 
-	if (!i2c_check_functionality(adapter, I2C_FUNC_I2C))
+	if (!i2c_check_functionality(adapter, I2C_FUNC_SMBUS_BYTE_DATA))
 		return -EIO;
 
 	if (pdata) {