The patch is to fix the "pkt" memory leak in packet_enqueue().
The allocated "pkt" needs to be freed if the colo compare
primary or secondary queue is too big.

Replace the error_report of full queue with a trace event.

Signed-off-by: Derek Su <dereksu@qnap.com>
Reviewed-by: Zhang Chen <chen.zhang@intel.com>
Reviewed-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Signed-off-by: Zhang Chen <chen.zhang@intel.com>
Signed-off-by: Jason Wang <jasowang@redhat.com>