tcg: dump op count into qemu log

fopen() may fail and it does not check its return vaule here,
it is better to dump op count to the normal log file.

Signed-off-by: Li Liu <john.liuli@huawei.com>
Signed-off-by: zhanghailiang <zhang.zhanghailiang@huawei.com>
Signed-off-by: Michael Tokarev <mjt@tls.msk.ru>
