Remove %clean section

None of currently supported distributions need that.
Last one was EL5 which is EOL for a while.

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

vamp-plugin-sdk.spec

@@ -77,9 +77,6 @@ make clean
 [ $(strings ${RPM_BUILD_ROOT}%{_libdir}/lib*.so.?|grep /lib|sed -e 's!/%{_lib}!/__FEDORA-LIB__!g'|grep -c /lib) -eq 0 ]
 
 
-%clean
-rm -rf $RPM_BUILD_ROOT
-
 
 %post -p /sbin/ldconfig