raop: Code cleanup: align indent levels of debug outputs
raop: Add some debug outputs at state transition
raop: Set poll timer when entering the RUNNING state

When pausing music, the raop module enters the IDLE state.
If you resume the music right after pausing, the module enters the RUNNING
state but the poll timer is left expired.
This prevents the main thread loop from sending audio packets.

To avoid this situation, set the poll timer again when the module enters
the RUNNING state.