tracing: perf: Have perf tracepoint callbacks always disable preemption

tracing: perf: Have perf tracepoint callbacks always disable preemption

In preparation to convert protection of tracepoints from being protected
by a preempt disabled section to being protected by SRCU, have all the
perf callbacks disable preemption as perf expects preemption to be
disabled when processing tracepoints.

While at it, convert the perf system call callback preempt_disable() to a
guard(preempt).

Link: https://lore.kernel.org/all/20250613152218.1924093-1-bigeasy@linutronix.de/
Link: https://patch.msgid.link/20260108220550.2f6638f3@fedora
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: "Paul E. McKenney" <paulmck@kernel.org>
Cc: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Cc: Alexei Starovoitov <ast@kernel.org>
Link: https://patch.msgid.link/20260126231256.174621257@kernel.org
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>