qemu: remove writing to QEMU log file for rename operation

qemu: remove writing to QEMU log file for rename operation

The rename operation only works on inactive virtual machines,
but it none the less writes to the log file used by the QEMU
processes. This log file is not intended to provide a general
purpose audit trail of operations performed on VMs. The audit
subsystem has recording of important operations. If we want
to extend that to cover all significant public APIs that is
a valid thing to consider, but we shouldn't arbitrarily log
specific APIs into the QEMU log file in the meantime.

Signed-off-by: Daniel P. Berrange <berrange@redhat.com>