Significantly reduce peak memory usage when vpacket logging is enabled.
Significantly reduce peak memory usage when vpacket logging is enabled.

Instead of allocating numpy arrays for the virt_packet* arrays all
at once, copying from the C arrays, and freeing the C arrays, simply
transfer ownership of the C array memory to a numpy array object.

With this fix, peak memory usage by virt_packet arrays is reduced to half.

kaushik94/tardis,kaushik94/tardis,kaushik94/tardis,kaushik94/tardis