ANDROID: GKI: remove export of tracing control functions

Android GKI kernel modules should NOT have the ability to control the
system-wide tracing functionality, nor query to determine if it is on or
not.  So remove the exports of these functions.

Upstream does not wish to do this, so an Android-only change is
required.  See the bug id for details.

Bug: 355584612
Signed-off-by: Greg Kroah-Hartman <gregkh@google.com>
Change-Id: I50f69cd9930ddc6b876c5c1dd86f51cfb2ee1bac

kernel/trace/trace.c

@@ -1039,7 +1039,6 @@ void tracing_on(void)
 {
 	tracer_tracing_on(&global_trace);
 }
-EXPORT_SYMBOL_GPL(tracing_on);
 
 
 static __always_inline void
@@ -1612,7 +1611,6 @@ int tracing_is_on(void)
 {
 	return tracer_tracing_is_on(&global_trace);
 }
-EXPORT_SYMBOL_GPL(tracing_is_on);
 
 static int __init set_buf_size(char *str)
 {