csip: Fix handling error on locking.

When one of the device locking will not succeed, we should unlocked
previously locked devices.
This patch fixes unlock state value which previously was 0x00 (unset)

Bug: 230426955
Test: atest BluetoothInstrumentationTests
Test: atest --host bluetooth_csis_test
Tag: #stability
Change-Id: I15f97d1ab79cecccfd20260de198e037db1506b1