staging: vt6656: replaced U_CRC_LEN with ETH_FCS_LEN

Removed custom macro with one from include/linux/if_ether.h.
FCS is an Ethernet field that holds the CRC value.

Signed-off-by: Andres More <more.andres@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
diff --git a/drivers/staging/vt6656/rxtx.c b/drivers/staging/vt6656/rxtx.c
index 6461d55..b20cdc6 100644
--- a/drivers/staging/vt6656/rxtx.c
+++ b/drivers/staging/vt6656/rxtx.c
@@ -3235,7 +3235,8 @@
     if (pDevice->wCurrentRate <= RATE_11M)
         byPktType = PK_TYPE_11B;
 
-    BytesToWrite = uDataLen + U_CRC_LEN;
+    BytesToWrite = uDataLen + ETH_FCS_LEN;
+
     // Convert the packet to an usb frame and copy into our buffer
     // and send the irp.