rpms: %exclude has side-effects, remove the files from buildroot instead

rpms: %exclude has side-effects, remove the files from buildroot instead

Due to the way debuginfo package creation is done in existing rpm
versions, its better to physically remove any non-packaged files
from the buildroot, using %exclude for the purposes causes artifacts
like broken symlinks  in the -debuginfo packages.

Reported-at: https://bugzilla.redhat.com/show_bug.cgi?id=1281913
Signed-off-by: Panu Matilainen <pmatilai@redhat.com>
Acked-by: Flavio Leitner <fbl@sysclose.org>
Signed-off-by: Ben Pfaff <blp@ovn.org>