I ran a git pull that ended in a conflict. I resolved the conflict and everything is fine now (I used mergetool also).
When I commit the resolved file
You probably got a conflict in something that you haven't staged for commit. git won't let you commit things independently (because it's all part of the merge, I guess), so you need to git add that file and then git commit -m "Merge conflict resolution". The -i flag for git commit does the add for you.