drivers: sensor: explorir_m: improve transceive

During calibration feature development the following loop was used for
testing:

```shell
CMD="sensor attr_set explorir_m co2 calibration 1234"
while : ; do echo "$CMD" > /dev/ttyACM0; sleep .8; done
```

At some point calibration would fail and all following calibration commands
would fail.

Reset buffer and semaphore just before terminating the command to better
mitigate disturbance from previous failed command.

Signed-off-by: Jeppe Odgaard <jeppe.odgaard@prevas.dk>

Author: Jeppe Odgaard

drivers/sensor/explorir_m/explorir_m.c

@@ -198,18 +198,6 @@ static void explorir_m_uart_terminate(const struct device *uart_dev)
 	uart_poll_out(uart_dev, EXPLORIR_M_END_CHAR);
 }
 
-static int explorir_m_await_receive(struct explorir_m_data *data)
-{
-	int rc = k_sem_take(&data->uart_rx_sem, K_MSEC(EXPLORIR_M_MAX_RESPONSE_DELAY));
-
-	/* Reset semaphore if sensor did not respond within maximum specified response time */
-	if (rc == -EAGAIN) {
-		k_sem_reset(&data->uart_rx_sem);
-	}
-
-	return rc;
-}
-
 static int explorir_m_uart_transceive(const struct device *dev, char type, struct sensor_value *val,
 				      enum explorir_m_uart_set_usage set)
 {
@@ -225,8 +213,6 @@ static int explorir_m_uart_transceive(const struct device *dev, char type, struc
 
 	k_mutex_lock(&data->uart_mutex, K_FOREVER);
 
-	explorir_m_buffer_reset(data);
-
 	uart_poll_out(cfg->uart_dev, type);
 
 	if (set == EXPLORIR_M_SET_VAL_ONE) {
@@ -246,9 +232,12 @@ static int explorir_m_uart_transceive(const struct device *dev, char type, struc
 		uart_poll_out(cfg->uart_dev, buf[i]);
 	}
 
+	explorir_m_buffer_reset(data);
+	k_sem_reset(&data->uart_rx_sem);
+
 	explorir_m_uart_terminate(cfg->uart_dev);
 
-	rc = explorir_m_await_receive(data);
+	rc = k_sem_take(&data->uart_rx_sem, K_MSEC(EXPLORIR_M_MAX_RESPONSE_DELAY));
 	if (rc != 0) {
 		LOG_WRN("%c did not receive a response: %d", type, rc);
 	}