loguserdata: handle exceptions from running the userdata

- log the exceptions so the user can diagnose issues.

bug 1154641
Change-Id: Ic085c9f062255a9fa44b3e31b464c9ebd19a947c
Signed-off-by: Angus Salkeld <asalkeld@redhat.com>
Merge "loguserdata: handle exceptions from running the userdata"