I think there is something missing in the Wiki. Probably the author had already done the export of the following parameter and has forgotten about is? This is how I did it (nowadays I add some extra things to the kernel package):
compile:/usr/src/kernel-source-2.6.8# cp -a ../configs/kernel-2.6.8-022stab077-i686.config.ovz .config
compile:/usr/src/kernel-source-2.6.8# export PATCH_THE_KERNEL=YES
compile:/usr/src/kernel-source-2.6.8# make-kpkg --added-patches openvz --append-to-version -openvz-k7 --revision HK.1 --config oldconfig --initrd kernel_image
I've multiple configs, but I think that the main reason is the export command. Without it, nothing is patched