try to down hci0 before accessing it

use case: overwrite the default host address already set. In this case the
bt host is already up but needs the new address.

Signed-off-by: Jens Glathe <jglathe@oldschoolsolutions.biz>

bootmac

@@ -148,6 +148,12 @@ mac_generate() {
 mac_bluetooth() {
     log "setting Bluetooth MAC to $BT_MAC"
 
+    # Check if the Bluetooth interface is up
+    if hciconfig "$BT_INTERFACE" | grep -q "UP"; then
+        # Bring the Bluetooth interface down
+        hciconfig "$BT_INTERFACE" down
+    fi
+
     # Save current rfkill status, may return a non-zero exit code when blocked
     set +e
     BT_RFKILL_UNBLOCKED=$(rfkill -n -r -o DEVICE,TYPE,SOFT | grep "bluetooth" | grep "unblocked")