rpmdsMatchesDep() isn't correct on obsoletes

rpmdsMatchesDep() isn't correct on obsoletes

- Fix oversight in commit 9fb81eac0bcd239e46459f72916099f1adfc5cb9:
  rpmdsMatchesDep() works on provides, but obsoletes are matched on
  package name so we want rpmdsNVRMatchesDep(). rpmdsMatchesDep()
  "worked" as the implicit self-provide is always at the 0 index
  on packages created by modern rpmbuild, but this isn't really
  guaranteed: very old V3 rpms can have something else at the
  first index, and ditto for non-rpmbuild created packages.
- Thanks to Michael Schroeder for pointing this out.