canio: remove unused fields

these relate to properties that were removed as well

Author: jepler

ports/atmel-samd/common-hal/canio/CAN.h

@@ -41,9 +41,6 @@ typedef struct canio_can_obj {
     mp_obj_base_t base;
     Can *hw;
     canio_can_state_t *state;
-    volatile uint32_t error_warning_state_count;
-    volatile uint32_t error_passive_state_count;
-    volatile uint32_t bus_off_state_count;
     int baudrate;
     uint8_t rx_pin_number:8;
     uint8_t tx_pin_number:8;

ports/stm/common-hal/canio/CAN.h

@@ -42,9 +42,6 @@ typedef struct canio_can_obj {
     mp_obj_base_t base;
     CAN_HandleTypeDef handle;
     CAN_TypeDef *filter_hw;
-    volatile uint32_t error_warning_state_count;
-    volatile uint32_t error_passive_state_count;
-    volatile uint32_t bus_off_state_count;
     int baudrate;
     const mcu_pin_obj_t *rx_pin;
     const mcu_pin_obj_t *tx_pin;