Bluetooth: btrtl: Fix an issue that failing to download the FW which size is over 32K bytes

Fix the issue that when the FW size is 32K+, it will fail for the download
process because of the incorrect index.

When firmware patch length is over 32K, "dl_cmd->index" may >= 0x80. It
will be thought as "data end" that download process will not complete.
However, driver should recount the index from 1.
Signed-off-by: Max Chou <max.chou@realtek.com>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>

drivers/bluetooth/btrtl.c

@@ -401,7 +401,11 @@ static int rtl_download_firmware(struct hci_dev *hdev,
 
 		BT_DBG("download fw (%d/%d)", i, frag_num);
 
-		dl_cmd->index = i;
+		if (i > 0x7f)
+			dl_cmd->index = (i & 0x7f) + 1;
+		else
+			dl_cmd->index = i;
+
 		if (i == (frag_num - 1)) {
 			dl_cmd->index |= 0x80; /* data end */
 			frag_len = fw_len % RTL_FRAG_LEN;