Input: st1232 - do not allocate fingers data separately

The finger structure size is quite small and allocating it together with
the main driver structure will not increase likelyhood of allocation
failing, but reduces number of objects needing to be tracked by the
allocator and devm.
Tested-by: Matthias Fend <Matthias.Fend@wolfvision.net>
Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>

drivers/input/touchscreen/st1232.c

@@ -50,12 +50,12 @@ struct st1232_ts_data {
 	const struct st_chip_info *chip_info;
 	int read_buf_len;
 	u8 *read_buf;
-	struct st1232_ts_finger *finger;
+	struct st1232_ts_finger fingers[];
 };
 
 static int st1232_ts_read_data(struct st1232_ts_data *ts)
 {
-	struct st1232_ts_finger *finger = ts->finger;
+	struct st1232_ts_finger *finger = ts->fingers;
 	struct i2c_client *client = ts->client;
 	u8 start_reg = ts->chip_info->start_reg;
 	struct i2c_msg msg[] = {
@@ -98,7 +98,7 @@ static int st1232_ts_read_data(struct st1232_ts_data *ts)
 static irqreturn_t st1232_ts_irq_handler(int irq, void *dev_id)
 {
 	struct st1232_ts_data *ts = dev_id;
-	struct st1232_ts_finger *finger = ts->finger;
+	struct st1232_ts_finger *finger = ts->fingers;
 	struct input_dev *input_dev = ts->input_dev;
 	int count = 0;
 	int i, ret;
@@ -177,7 +177,6 @@ static int st1232_ts_probe(struct i2c_client *client,
 {
 	const struct st_chip_info *match;
 	struct st1232_ts_data *ts;
-	struct st1232_ts_finger *finger;
 	struct input_dev *input_dev;
 	int error;
 
@@ -199,16 +198,13 @@ static int st1232_ts_probe(struct i2c_client *client,
 		return -EINVAL;
 	}
 
-	ts = devm_kzalloc(&client->dev, sizeof(*ts), GFP_KERNEL);
+	ts = devm_kzalloc(&client->dev,
+			  struct_size(ts, fingers, match->max_fingers),
+			  GFP_KERNEL);
 	if (!ts)
 		return -ENOMEM;
 
 	ts->chip_info = match;
-	ts->finger = devm_kcalloc(&client->dev,
-				  ts->chip_info->max_fingers, sizeof(*finger),
-				  GFP_KERNEL);
-	if (!ts->finger)
-		return -ENOMEM;
 
 	/* allocate a buffer according to the number of registers to read */
 	ts->read_buf_len = ts->chip_info->max_fingers * 4;