Fix comma at end of enumerator list warning.
Fix comma at end of enumerator list warning.

svn path=/trunk/libcss/; revision=13709

prepare/netsurf_libcss,servo/libcss,servo/libcss,zhuyadong/libcss,prepare/netsurf_libcss,zhuyadong/libcss,servo/libcss,prepare/netsurf_libcss,zhuyadong/libcss