[PATCH] I2C: Fix i2c_use_client()

i2c_use_client() contains a bogosity.  If i2c_inc_use_client() returns
success, i2c_use_client() returns an error.  If i2c_inc_use_client()
fails, i2c_use_client() might succeed.

Fix it so that (a) we get the correct sense between these two functions,
and (b) propagate the error code from i2c_inc_use_client(), rather than
making our own one up.

drivers/i2c/i2c-core.c

@@ -437,8 +437,11 @@ static void i2c_dec_use_client(struct i2c_client *client)
 
 int i2c_use_client(struct i2c_client *client)
 {
-	if (!i2c_inc_use_client(client))
-		return -ENODEV;
+	int ret;
+
+	ret = i2c_inc_use_client(client);
+	if (ret)
+		return ret;
 
 	if (client->flags & I2C_CLIENT_ALLOW_USE) {
 		if (client->flags & I2C_CLIENT_ALLOW_MULTIPLE_USE)