staging: pi433: remove unnecessary calling rf69_set_mode()

Remove unnecessary rf69_set_mode() function call when rx is waiting for
a telegram. There is waste to call rf69_set_mode() twice for becoming
standby mode.
Signed-off-by: Sidong Yang <realwakka@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/staging/pi433/pi433_if.c

@@ -650,21 +650,19 @@ pi433_tx_thread(void *data)
 		disable_irq(device->irq_num[DIO0]);
 		device->tx_active = true;
 
+		/* clear fifo, set fifo threshold, set payload length */
+		retval = rf69_set_mode(spi, standby); /* this clears the fifo */
+		if (retval < 0)
+			return retval;
+
 		if (device->rx_active && !rx_interrupted) {
 			/*
 			 * rx is currently waiting for a telegram;
 			 * we need to set the radio module to standby
 			 */
-			retval = rf69_set_mode(device->spi, standby);
-			if (retval < 0)
-				return retval;
 			rx_interrupted = true;
 		}
 
-		/* clear fifo, set fifo threshold, set payload length */
-		retval = rf69_set_mode(spi, standby); /* this clears the fifo */
-		if (retval < 0)
-			return retval;
 		retval = rf69_set_fifo_threshold(spi, FIFO_THRESHOLD);
 		if (retval < 0)
 			return retval;