Megatron fixes: lazy init moved back to module for inference to work
This pull request **introduces 1 alert** when merging 39fe1a548baa62507241a391b05d471ab05d5d76 into 719e21d402679e0edbdb7fdcc41c5bcd4af295d8 - [view on LGTM.com](https://lgtm.com/projects/g/NVIDIA/NeMo/rev/pr-5b66e21ee1c4104cca572d02b00a48546f1e7c3b)

**new alerts:**

* 1 for Unused local variable
lazy int() only during fit() led to failures in forward() for inference scripts.

Signed-off-by: Boris Fomitchev <bfomitchev@nvidia.com>