hrtimers: Rename __hrtimer_init_sleeper() to __hrtimer_setup_sleeper()

All the hrtimer_init*() functions have been renamed to hrtimer_setup*().
Rename __hrtimer_init_sleeper() to __hrtimer_setup_sleeper() as well, to
keep the names consistent.

Signed-off-by: Nam Cao <namcao@linutronix.de>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Link: https://lore.kernel.org/all/807694aedad9353421c4a7347629a30c5c31026f.1738746927.git.namcao@linutronix.de