Fix tracing

Fix tracing

* module/system/vm/trace.scm (print-return): Remove frame argument.
  (trace-calls-to-procedure, trace-calls-in-procedure): Adapt callers.
* module/system/vm/traps.scm (trap-in-procedure, trap-frame-finish):
  (trap-calls-to-procedure): Since the pop continuation hook is now
  called after the continuation is popped, we need to check the right
  frame.  Fixes tail-calls in the trace root, and probably other things.