AP_HAL_ESP32: re-order initialiser lines so -Werror=reorder will work

libraries/AP_HAL_ESP32/DeviceBus.cpp

@@ -31,7 +31,8 @@ using namespace ESP32;
 extern const AP_HAL::HAL& hal;
 
 DeviceBus::DeviceBus(uint8_t _thread_priority) :
-    thread_priority(_thread_priority), semaphore()
+    semaphore(),
+    thread_priority(_thread_priority)
 {
 #ifdef BUSDEBUG
     printf("%s:%d \n", __PRETTY_FUNCTION__, __LINE__);

libraries/AP_HAL_ESP32/I2CDevice.cpp

@@ -59,9 +59,9 @@ I2CDeviceManager::I2CDeviceManager(void)
 }
 
 I2CDevice::I2CDevice(uint8_t busnum, uint8_t address, uint32_t bus_clock, bool use_smbus, uint32_t timeout_ms) :
+    bus(I2CDeviceManager::businfo[busnum]),
     _retries(10),
-    _address(address),
-    bus(I2CDeviceManager::businfo[busnum])
+    _address(address)
 {
     set_device_bus(busnum);
     set_device_address(address);