Free Http2Stream directly when HttpSM is already gone or not allocated
Free Http2Stream directly when HttpSM is already gone or not allocated

When Http2Stream get error before it start transaction, Http2Stream::transaction_done() is never called.
Because HttpSM is not allocated. In regular cases, Http2Stream::initiating_close() signal some events
to HttpSM, but in above case it should free itself directly.

SolidWallOfCode/trafficserver,vmamidi/trafficserver,bryancall/trafficserver,davidbz/trafficserver,chitianhao/trafficserver,persiaAziz/trafficserver,pbchou/trafficserver,vmamidi/trafficserver,dyrock/trafficserver,dyrock/trafficserver,pbchou/trafficserver,SolidWallOfCode/trafficserver,chitianhao/trafficserver,dyrock/trafficserver,chitianhao/trafficserver,persiaAziz/trafficserver,bryancall/trafficserver,persiaAziz/trafficserver,pbchou/trafficserver,chitianhao/trafficserver,SolidWallOfCode/trafficserver,persiaAziz/trafficserver,pbchou/trafficserver,vmamidi/trafficserver,davidbz/trafficserver,persiaAziz/trafficserver,dyrock/trafficserver,duke8253/trafficserver,bryancall/trafficserver,bryancall/trafficserver,davidbz/trafficserver,vmamidi/trafficserver,persiaAziz/trafficserver,davidbz/trafficserver,duke8253/trafficserver,SolidWallOfCode/trafficserver,duke8253/trafficserver,vmamidi/trafficserver,davidbz/trafficserver,pbchou/trafficserver,dyrock/trafficserver,SolidWallOfCode/trafficserver,vmamidi/trafficserver,bryancall/trafficserver,SolidWallOfCode/trafficserver,chitianhao/trafficserver,persiaAziz/trafficserver,SolidWallOfCode/trafficserver,duke8253/trafficserver,dyrock/trafficserver,chitianhao/trafficserver,dyrock/trafficserver,duke8253/trafficserver,persiaAziz/trafficserver,pbchou/trafficserver,bryancall/trafficserver,davidbz/trafficserver,duke8253/trafficserver,chitianhao/trafficserver,duke8253/trafficserver