Minor non functional refactorings to ftrace parser

Isolating self-contained changes to ftrace parser
off the big flush CL. No functional change is introduced
by this CL.

Bug: 73886018
Bug: 73452932
Change-Id: Iff092663e3cca9ff165cb568331441d968e027d4
diff --git a/src/traced/probes/ftrace/ftrace_controller.h b/src/traced/probes/ftrace/ftrace_controller.h
index 15d7dde..b1845ce 100644
--- a/src/traced/probes/ftrace/ftrace_controller.h
+++ b/src/traced/probes/ftrace/ftrace_controller.h
@@ -49,6 +49,8 @@
 // Utility class for controlling ftrace.
 class FtraceController {
  public:
+  static const char* const kTracingPaths[];
+
   class Observer {
    public:
     virtual ~Observer();