tracing/stacktrace: improve help text

	select FTRACE

	select STACKTRACE

	help

	  This tracer records the max stack of the kernel, and displays

	  it in debugfs/tracing/stack_trace

	  This special tracer records the maximum stack footprint of the

	  kernel and displays it in debugfs/tracing/stack_trace.

	  This tracer works by hooking into every function call that the

	  kernel executes, and keeping a maximum stack depth value and

	  stack-trace saved. Because this logic has to execute in every

	  kernel function, all the time, this option can slow down the

	  kernel measurably and is generally intended for kernel

	  developers only.

	  Say N if unsure.

config DYNAMIC_FTRACE

	bool "enable/disable ftrace tracepoints dynamically"