RFR(XS): Remove unused ShenandoahPrinter

[Zhengyu Gu]

Removed no longer used ShenandoahPrinter

http://cr.openjdk.java.net/~zgu/shenandoah/rm_sh_printer/webrev.00/

Test:
   Clean builds: fastdebug and release
   hotspot_gc_shenandoah


Thanks,

-Zhengyu