staging: pi433: Rename struct pi433_device buffer field to tx_buffer.

Driver holds buffers in different structs, as does the HW.
Using explicit names for buffers increases readability.
Signed-off-by: Shahar Avidar <ikobh7@gmail.com>
Reviewed-by: Dan Carpenter <dan.carpenter@linaro.org>
Link: https://lore.kernel.org/r/20240405074000.3481217-2-ikobh7@gmail.comSigned-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/staging/pi433/pi433_if.c

@@ -89,7 +89,7 @@ struct pi433_device {
 	struct task_struct	*tx_task_struct;
 	wait_queue_head_t	tx_wait_queue;
 	u8			free_in_fifo;
-	char			buffer[MAX_MSG_SIZE];
+	char			tx_buffer[MAX_MSG_SIZE];
 
 	/* rx related values */
 	struct pi433_rx_cfg	rx_cfg;
@@ -612,8 +612,8 @@ static int pi433_tx_thread(void *data)
 		if (tx_cfg.enable_address_byte == OPTION_ON)
 			size++;
 
-		/* prime buffer */
-		memset(device->buffer, 0, size);
+		/* prime tx_buffer */
+		memset(device->tx_buffer, 0, size);
 		position = 0;
 
 		/* add length byte, if requested */
@@ -622,15 +622,15 @@ static int pi433_tx_thread(void *data)
 			 * according to spec, length byte itself must be
 			 * excluded from the length calculation
 			 */
-			device->buffer[position++] = size - 1;
+			device->tx_buffer[position++] = size - 1;
 
 		/* add adr byte, if requested */
 		if (tx_cfg.enable_address_byte == OPTION_ON)
-			device->buffer[position++] = tx_cfg.address_byte;
+			device->tx_buffer[position++] = tx_cfg.address_byte;
 
 		/* finally get message data from fifo */
-		retval = kfifo_out(&device->tx_fifo, &device->buffer[position],
-				   sizeof(device->buffer) - position);
+		retval = kfifo_out(&device->tx_fifo, &device->tx_buffer[position],
+				   sizeof(device->tx_buffer) - position);
 		dev_dbg(device->dev,
 			"read %d message byte(s) from fifo queue.\n", retval);
 
@@ -714,7 +714,7 @@ static int pi433_tx_thread(void *data)
 
 				device->free_in_fifo = 0;
 				rf69_write_fifo(spi,
-						&device->buffer[position],
+						&device->tx_buffer[position],
 						write_size);
 				position += write_size;
 			} else {
@@ -722,7 +722,7 @@ static int pi433_tx_thread(void *data)
 				device->free_in_fifo -= size;
 				repetitions--;
 				rf69_write_fifo(spi,
-						&device->buffer[position],
+						&device->tx_buffer[position],
 						(size - position));
 				position = 0; /* reset for next repetition */
 			}