with one or more versions of rpm-build being installed. To clean up, you could temporary remove the offending packages (the ones that have the unmet dependency), and try to reinstall them later (if required).

rpm -qa rpm-build would give a list (or rpm -qa| grep rpm-build), then use rpm --erase rpm-build-4.3.3-13_nonptl to remove the package (give the full version in case there were several matches). Please do not use --nodeps when removing, as this is bound to leave the system RPM database in an inconsistent state.

You can then re-run the update via yum update and see whether the recently-removed RPM gets added again (hopefully for a new/fixed version), or run yum install rpm-build manually later (in case you require this package, but the system would be consistent even without). Or you leave it simply off - one RPM less to update.

The YUM FAQ has some more information on this.