Description of problem:
Trying to rebuild source-rpms with installed but not packaged files fails on phoebe.

Testcase:
rpmbuild --rebuild librpm404-4.0.4-8x.27.src.rpm (from Psyche) fails.
The complete buildlog is at http://filepile.dicp.de/rpmbuild.log and
shows that everything runs fine until the end of the %install stage.

The %install stage executes and finished successfully but after checking
for installed but not packaged files the build stops.
It seems that the not-packaged files are being recognized as errors and
not as warnings, something which is not the case with the 8.0
distribution.

Version-Release number of selected component (if applicable): rpm-4.2.0-68

How reproducible: always


Steps to Reproduce:
1. Take a src-rpm which builds cleanly. pident for example as it is small an
builds fast.
2. Comment out one or two files in the %files section. (example testcase at
http://filepile.dicp.de/pidentd-3.0.16-1nousername.src.rpm )
3. rpmbuild -ba $SPECFILE
    
Actual results: Rebuilding stops because of errors

Expected results: Rebuilding continues with warnings

Additional info: Suggested workaround:
Adding "%_unpackaged_files_terminate_build    0" to ~/.rpmmacros or /etc/rpm/macros