OCI runtime spec defines memory.swap as 'limit of memory+Swap usage'
so setting them to equal should disable the swap. Also, this change
should make containerd behaviour same as other runtimes e.g
'cri-dockerd/dockershim' and won't be impacted when user turn on
'NodeSwap' (https://github.com/kubernetes/enhancements/issues/2400) feature.
Signed-off-by: Qasim Sarfraz <qasimsarfraz@microsoft.com>