ZIL fixes

[gllghr]

While doing some other testing, I noticed that a couple things in the zil script needed fixing:

• The path to the bcc helper needs to be updated, similar to what was done for the stbtrace programs in Use copy of bcc_helper.h from performance-diagnositics #27.
• The flags used to determine if a write is synchronous or not need to be updated, similar to what was done in Fix ZPL Collectors after ZFS changes to sync flags and include files #21.

ab-pre-push: http://selfservice.jenkins.delphix.com/job/devops-gate/job/master/job/appliance-build-orchestrator-pre-push/2697/