Bluetooth: btusb: Fix a unspported condition to set available debug features

When reading the support debug features failed, there are not available
features init. Continue to set the debug features is illogical, we should
skip btintel_set_debug_features(), even if check it by "if (!features)".

Fixes: c453b10c

 ("Bluetooth: btusb: Configure Intel debug feature based on available support")
Signed-off-by: Jun Miao <jun.miao@windriver.com>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>