kvm tools: Move memory stat print to client

So far we were printing memory statistics in the terminal of the guest,
this was annoying, confusing and inneficient.

This patch moves the print to the terminal which ran 'kvm stat'

Signed-off-by: Sasha Levin <levinsasha928@gmail.com>
Signed-off-by: Pekka Enberg <penberg@kernel.org>