KVM: Clarify the lifetime of a mapping vs that of a memslot

Removing a mapping from a live memslot is a sure way for a guest
to terminate quicker than you expect. Document that doing so
is a programming error.

Wilst we're at it, inform the reader that KVM_SET_MEMORY_REGION
has passed away.

Signed-off-by: Marc Zyngier <maz@kernel.org>
1 file changed