perf sched replay: Remove unused parts of the code

perf sched replay: Remove unused parts of the code

The sleep_sem semaphore and the specific_wait field (member of sched_atom)
are initialized but not used anywhere in the code, so this patch removes
them.

The SCHED_EVENT_MIGRATION case in perf_sched__process_event() is currently
not used and is also removed.

Additionally, prev_state in add_sched_event_sleep() is marked with
__maybe_unused and is not utilized anywhere in the function. This patch
removes the parameter.

If the task_state parameter was intended for future use, it can be
reintroduced when needed.

No functionality change intended.

Signed-off-by: Madadi Vineeth Reddy <vineethr@linux.ibm.com>
Cc: Athira Rajeev <atrajeev@linux.vnet.ibm.com>
Link: https://lore.kernel.org/r/20240917090100.42783-1-vineethr@linux.ibm.com
Signed-off-by: Namhyung Kim <namhyung@kernel.org>