V4L/DVB (8893): pvrusb2: Add comment elaborating on direct use of swab32()

		if (bcnt > FIRMWARE_CHUNK_SIZE) bcnt = FIRMWARE_CHUNK_SIZE;

		memcpy(fw_ptr, fw_entry->data + fw_done, bcnt);

		/* Usbsnoop log shows that we must swap bytes... */

		/* Some background info: The data being swapped here is a

		   firmware image destined for the mpeg encoder chip that

		   lives at the other end of a USB endpoint.  The encoder

		   chip always talks in 32 bit chunks and its storage is

		   organized into 32 bit words.  However from the file

		   system to the encoder chip everything is purely a byte

		   stream.  The firmware file's contents are always 32 bit

		   swapped from what the encoder expects.  Thus the need

		   always exists to swap the bytes regardless of the endian

		   type of the host processor and therefore swab32() makes

		   the most sense. */

		for (icnt = 0; icnt < bcnt/4 ; icnt++)

			((u32 *)fw_ptr)[icnt] = swab32(((u32 *)fw_ptr)[icnt]);