Remove unneeded files

Signed-off-by: Igor Gnatenko <ignatenkobrain@fedoraproject.org>

rust-onig_sys.spec

@@ -88,6 +88,7 @@ which use "print-debug" feature of "%{crate}" crate.
 %prep
 %autosetup -n %{crate}-%{version_no_tilde} -p1
 #rm -vrf oniguruma/
+find oniguruma/ -mindepth 1 -maxdepth 1 -not -name 'src' -not -name 'COPYING' | xargs rm -vrf
 find oniguruma/ -type f -executable -exec chmod -x {} \+
 %cargo_prep