locking/rt: Annotate unlock followed by lock for sparse.

rt_mutex_slowlock_block() and rtlock_slowlock_locked() both unlock
lock::wait_lock and then lock it later. This is unusual and sparse
complains about it.

Add __releases() + __acquires() annotation to mark that it is expected.

Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Link: https://lore.kernel.org/all/20240812104200.2239232-5-bigeasy@linutronix.de