Added usr/sbin, needed for atopacctd.
debian/rules: Also clean atopsar symlink and atopacctd to fix dpkg-source errors:

dpkg-source: info: using options from atop.git/debian/source/local-options: --unapply-patches
dpkg-source: info: using source format `3.0 (quilt)'
dpkg-source: info: building atop using existing ./atop_2.1.orig.tar.gz
dpkg-source: error: cannot represent change to atopsar:
dpkg-source: error:   new version is symlink to atop
dpkg-source: error:   old version is nonexistent
dpkg-source: error: cannot represent change to atopacctd: binary file contents changed
dpkg-source: error: add atopacctd in debian/source/include-binaries if you want to store the modified binary in the debian tarball
dpkg-source: error: unrepresentable changes to source