infrun.c: simplify "end stepping range" code a bit.

infrun.c: simplify "end stepping range" code a bit.

 - all end_stepping_range callers also set stop_step.

 - all places that set stop_step call end_stepping_range and
   stop_waiting too.

IOW, all places where we handle "end stepping range" do:

      ecs->event_thread->control.stop_step = 1;
      end_stepping_range ();
      stop_waiting (ecs);

Factor that out into end_stepping_range itself.

Tested on x86_64 Fedora 20.

gdb/
2014-05-29  Pedro Alves  <palves@redhat.com>

	* infrun.c (process_event_stop_test, handle_step_into_function)
	(handle_step_into_function_backward): Adjust.
	Don't set the even thread's stop_step and call stop_waiting before
	calling end_stepping_range.  Instead do that ...
	(end_stepping_range): ... here.  Take an ecs pointer parameter.