tools/kvm_stat: use canonical ftrace path

The canonical location for the tracefs filesystem is at /sys/kernel/tracing.

But, from Documentation/trace/ftrace.rst:

  Before 4.1, all ftrace tracing control files were within the debugfs
  file system, which is typically located at /sys/kernel/debug/tracing.
  For backward compatibility, when mounting the debugfs file system,
  the tracefs file system will be automatically mounted at:

  /sys/kernel/debug/tracing

A comment in kvm_stat still refers to this older debugfs path, so let's
update it to avoid confusion.

Link: https://lkml.kernel.org/r/20230313211746.1541525-3-zwisler@kernel.org

Cc: "Tobin C. Harding" <me@tobin.cc>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Shuah Khan <shuah@kernel.org>
Cc: Tycho Andersen <tycho@tycho.pizza>
Acked-by: Paolo Bonzini <pbonzini@redhat.com>
Reviewed-by: Steven Rostedt (Google) <rostedt@goodmis.org>
Reviewed-by: Mukesh Ojha <quic_mojha@quicinc.com>
Signed-off-by: Ross Zwisler <zwisler@google.com>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>

tools/kvm/kvm_stat/kvm_stat

@@ -627,7 +627,7 @@ class TracepointProvider(Provider):
         name)'.
 
         All available events have directories under
-        /sys/kernel/debug/tracing/events/ which export information
+        /sys/kernel/tracing/events/ which export information
         about the specific event. Therefore, listing the dirs gives us
         a list of all available events.