stm32/usbdev: Remove unused RxState variable, and unused struct.

ports/stm32/usbdev/class/inc/usbd_cdc_msc_hid.h

@@ -44,20 +44,11 @@
 #define CDC_OUT_EP    (0x03)
 #define CDC_CMD_EP    (0x82)
 
-typedef struct {
-  uint32_t bitrate;
-  uint8_t  format;
-  uint8_t  paritytype;
-  uint8_t  datatype;
-} USBD_CDC_LineCodingTypeDef;
-
 typedef struct {
   uint32_t data[CDC_DATA_MAX_PACKET_SIZE / 4]; // Force 32bits alignment
   uint8_t  CmdOpCode;
   uint8_t  CmdLength;    
-  
   volatile uint32_t TxState;
-  volatile uint32_t RxState;
 } USBD_CDC_HandleTypeDef;
 
 typedef struct _USBD_STORAGE {

ports/stm32/usbdev/class/src/usbd_cdc_msc_hid.c

@@ -706,7 +706,6 @@ static uint8_t USBD_CDC_MSC_HID_Init(USBD_HandleTypeDef *pdev, uint8_t cfgidx) {
 
         // Init Xfer states
         usbd->CDC_ClassData.TxState = 0;
-        usbd->CDC_ClassData.RxState = 0;
 
         // Prepare Out endpoint to receive next packet
         USBD_LL_PrepareReceive(pdev, CDC_OUT_EP, buf, mp);