MB-11447: Don't close db handle if rollback header fails
MB-11447: Don't close db handle if rollback header fails

This happens automatically in couchstore and will cause a segfault
if we try to close the handle again.

Change-Id: I4e0f756749951ac869861fc150303b9df594ca65
Reviewed-on: http://review.couchbase.org/38377
Reviewed-by: abhinav dangeti <d73ef2279de6577f7bf081737ee47554bbb7dc82@couchbase.com>
Tested-by: Michael Wiederhold <a17fed27eaa842282862ff7c1b9c8395a26ac320@couchbase.com>

membase/ep-engine,membase/ep-engine,daverigby/ep-engine,hisundar/ep-engine,owendCB/ep-engine,owendCB/ep-engine,daverigby/kv_engine,jimwwalker/ep-engine,daverigby/kv_engine,couchbase/ep-engine,couchbase/ep-engine,hisundar/ep-engine,owendCB/ep-engine,daverigby/kv_engine,couchbase/ep-engine,hisundar/ep-engine,jimwwalker/ep-engine,sriganes/ep-engine,sriganes/ep-engine,sriganes/ep-engine,daverigby/ep-engine,sriganes/ep-engine,jimwwalker/ep-engine,daverigby/ep-engine,membase/ep-engine,teligent-ru/ep-engine,daverigby/kv_engine,teligent-ru/ep-engine,owendCB/ep-engine,membase/ep-engine,teligent-ru/ep-engine,jimwwalker/ep-engine,teligent-ru/ep-engine,hisundar/ep-engine,couchbase/ep-engine,daverigby/ep-engine