I just did the same thing on a Fedora 22 system. I couldn’t upgrade or reinstall any of the packages. Running package-cleanup –cleandups wanted to remove glibc, which wanted to pretty much all of the packages on the system.
To resolve the issue, I performed a distro-sync on all of the duplicate packages.
sudo package-cleanup --dupes | perl -pe 's/-\d+.*$//' | sort -u | grep -vP '^Loaded' | xargs sudo dnf distro-sync -y
Then followed up with
sudo dnf upgrade sudo package-cleanup --cleandupes