[PATCH] trace: eradicate noisy warning in trace_osnoise.c

[Randy Dunlap]

OK, I'm officially tired of this noise warning coming from
trace_osnoise.c, so shut it up. Also, adding new warnings is not OK.

../kernel/trace/trace_osnoise.c: In function ‘start_kthread’:
../kernel/trace/trace_osnoise.c:1461:8: warning: ‘main’ is usually a function [-Wmain]
  void *main = osnoise_main;
        ^~~~

Fixes: c8895e271f79 ("trace/osnoise: Support hotplug operations")
Signed-off-by: Randy Dunlap <rdunlap@xxxxxxxxxxxxx>
Suggested-by: Matthew Wilcox <willy@xxxxxxxxxxxxx>
Cc: Steven Rostedt <rostedt@xxxxxxxxxxx>
Cc: Ingo Molnar <mingo@xxxxxxxxxx>
Cc: Daniel Bristot de Oliveira <bristot@xxxxxxxxxx>
---
 kernel/trace/Makefile |    2 ++
 1 file changed, 2 insertions(+)

--- mmotm-2021-0728-1824.orig/kernel/trace/Makefile
+++ mmotm-2021-0728-1824/kernel/trace/Makefile
@@ -36,6 +36,8 @@ CFLAGS_bpf_trace.o := -I$(src)
 CFLAGS_trace_benchmark.o := -I$(src)
 CFLAGS_trace_events_filter.o := -I$(src)
 
+CFLAGS_trace_osnoise.o := -Wno-main
+
 obj-$(CONFIG_TRACE_CLOCK) += trace_clock.o
 
 obj-$(CONFIG_FUNCTION_TRACER) += libftrace.o