Because the cursor is set to delete one ServiceLogID at a time.
Even after reading the comments, I'm not sure that it's a good solution, but I don't know the entire story.
Luis C.
General Disclaimer:
Are you seriously taking the advice and code from someone from the internet without testing it? Do you at least understand it? Or can it easily kill your server?
How to post data/code on a forum to get the best help: Option 1 / Option 2