trace: Use pr_warn instead of pr_warning

As said in commit f2c2cbcc35 ("powerpc: Use pr_warn instead of
pr_warning"), removing pr_warning so all logging messages use a
consistent <prefix>_warn style. Let's do it.

Link: http://lkml.kernel.org/r/20191018031850.48498-26-wangkefeng.wang@huawei.com
To: linux-kernel@vger.kernel.org
Cc: Ingo Molnar <mingo@redhat.com>
Signed-off-by: Kefeng Wang <wangkefeng.wang@huawei.com>
Acked-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
Reviewed-by: Sergey Senozhatsky <sergey.senozhatsky@gmail.com>
Signed-off-by: Petr Mladek <pmladek@suse.com>

kernel/trace/trace_benchmark.c

@@ -178,14 +178,14 @@ static int benchmark_event_kthread(void *arg)
 int trace_benchmark_reg(void)
 {
 	if (!ok_to_run) {
-		pr_warning("trace benchmark cannot be started via kernel command line\n");
+		pr_warn("trace benchmark cannot be started via kernel command line\n");
 		return -EBUSY;
 	}
 
 	bm_event_thread = kthread_run(benchmark_event_kthread,
 				      NULL, "event_benchmark");
 	if (IS_ERR(bm_event_thread)) {
-		pr_warning("trace benchmark failed to create kernel thread\n");
+		pr_warn("trace benchmark failed to create kernel thread\n");
 		return PTR_ERR(bm_event_thread);
 	}