tracing/osnoise: Remove PREEMPT_RT ifdefs from inside functions

Remove CONFIG_PREEMPT_RT from inside functions, avoiding
compilation problems in the future.

Link: https://lkml.kernel.org/r/37ee0881b033cdc513efc84ebea26cf77880c8c2.1635702894.git.bristot@kernel.org

Cc: Ingo Molnar <mingo@redhat.com>
Cc: Tom Zanussi <zanussi@kernel.org>
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Juri Lelli <juri.lelli@redhat.com>
Cc: Clark Williams <williams@redhat.com>
Cc: John Kacur <jkacur@redhat.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Cc: Daniel Bristot de Oliveira <bristot@kernel.org>
Cc: linux-rt-users@vger.kernel.org
Cc: linux-trace-devel@vger.kernel.org
Cc: linux-kernel@vger.kernel.org
Suggested-by: Steven Rostedt <rostedt@goodmis.org>
Signed-off-by: Daniel Bristot de Oliveira <bristot@kernel.org>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>

kernel/trace/trace_osnoise.c

@@ -1518,9 +1518,11 @@ static enum hrtimer_restart timerlat_irq(struct hrtimer *timer)
 	 * running, the thread needs to receive the softirq delta_start. The
 	 * reason being is that the softirq will be the last to be unfolded,
 	 * resseting the thread delay to zero.
+	 *
+	 * The PREEMPT_RT is a special case, though. As softirqs run as threads
+	 * on RT, moving the thread is enough.
 	 */
-#ifndef CONFIG_PREEMPT_RT
-	if (osn_var->softirq.delta_start) {
+	if (!IS_ENABLED(CONFIG_PREEMPT_RT) && osn_var->softirq.delta_start) {
 		copy_int_safe_time(osn_var, &osn_var->thread.delta_start,
 				   &osn_var->softirq.delta_start);
 
@@ -1530,13 +1532,6 @@ static enum hrtimer_restart timerlat_irq(struct hrtimer *timer)
 		copy_int_safe_time(osn_var, &osn_var->thread.delta_start,
 				    &osn_var->irq.delta_start);
 	}
-#else /* CONFIG_PREEMPT_RT */
-	/*
-	 * The sofirqs run as threads on RT, so there is not need
-	 * to keep track of it.
-	 */
-	copy_int_safe_time(osn_var, &osn_var->thread.delta_start, &osn_var->irq.delta_start);
-#endif /* CONFIG_PREEMPT_RT */
 
 	/*
 	 * Compute the current time with the expected time.