Use 'mv' instead of 'cp' for backing up builds

Move RPMs instead of copying. Moving saves time and disk space and preserves the original build timestamps.

Author: sergiomb2

mock/py/mockbuild/buildroot.py

@@ -1060,8 +1060,9 @@ def delete(self):
                     file_util.mkdirIfAbsent(dstdir)
                     rpms = glob.glob(os.path.join(srcdir, "*rpm"))
                     if len(rpms) > 0:
-                        self.state.state_log.info("backup_results: saving with cp %s %s", " ".join(rpms), dstdir)
-                        util.run(cmd="cp %s %s" % (" ".join(rpms), dstdir))
+                        self.state.state_log.info("backup_results: saving with mv %s %s", " ".join(rpms), dstdir)
+                        for rpm in rpms:
+                           shutil.move(rpm, dstdir)
 
             p = self.make_chroot_path()
             self._lock_buildroot(exclusive=True)