Bluetooth: btusb: Fix failing to init controllers with operation firmware

Some firmware when operation don't may have broken versions leading to
error like the following:

[    6.176482] Bluetooth: hci0: Firmware revision 0.0 build 121 week 7 2021
[    6.177906] bluetooth hci0: Direct firmware load for intel/ibt-20-0-0.sfi failed with error -2
[    6.177910] Bluetooth: hci0: Failed to load Intel firmware file intel/ibt-20-0-0.sfi (-2)

Since we load the firmware file just to check if its version had changed
comparing to the one already loaded we can just skip since the firmware
is already operation.

Fixes: ac056546

 ("Bluetooth: btintel: Check firmware version before
download")
Signed-off-by: Luiz Augusto von Dentz <luiz.von.dentz@intel.com>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>