Fix calculation of minimum in colo_compare_tcp

GitHub's CodeQL reports a critical error which is fixed by using the MIN macro:

    Unsigned difference expression compared to zero

Signed-off-by: Stefan Weil <sw@weilnetz.de>
Cc: qemu-stable@nongnu.org
Reviewed-by: Zhang Chen <chen.zhang@intel.com>
Signed-off-by: Jason Wang <jasowang@redhat.com>
1 file changed