Fix integration when missing criu
Fix integration when missing criu

If criu isn't installed in the host, integration tests won't be able
to go on, it should skip checkpoint/restore tests instead of interrupt.

Output before:

```
$ make localintegration
bats -t tests/integration
/usr/lib/bats/bats-exec-suite: line 20: let: count+=: syntax error:
operand expected (error token is "+=")
Makefile:103: recipe for target 'localintegration' failed
```

Signed-off-by: Zhang Wei <14976e959b2860fb06a3c1edbdb1945a4e11b8b5@huawei.com>

mheon/runc,stefanberger/runc,hqhq/runc,mYmNeo/runc,mheon/runc,hqhq/runc,mikebrow/runc,crosbymichael/runc,opencontainers/runc,dqminh/runc,dqminh/runc,rhatdan/runc,estesp/runc,rhatdan/runc,mikebrow/runc,justincormack/runc,laijs/runc,kolyshkin/runc,adrianreber/runc,justincormack/runc,cyphar/runc,adrianreber/runc,dqminh/runc,crosbymichael/runc,sunyuan3/runc,xiaochenshen/runc,wking/runc,dqminh/runc,justincormack/runc,rajasec/runc,docker/runc,rhatdan/runc,stefanberger/runc,kolyshkin/runc,mYmNeo/runc,xiaochenshen/runc,rajasec/runc,estesp/runc,mikebrow/runc,kolyshkin/runc,estesp/runc,rajasec/runc,crosbymichael/runc,sunyuan3/runc,opencontainers/runc,hqhq/runc,cloudfoundry-incubator/runc,cyphar/runc,opencontainers/runc,laijs/runc,opencontainers/runc,xiaochenshen/runc,cyphar/runc,wking/runc,stefanberger/runc,adrianreber/runc,docker/runc,cloudfoundry-incubator/runc,wking/runc,sunyuan3/runc,laijs/runc,mYmNeo/runc,docker/runc,cloudfoundry-incubator/runc,kolyshkin/runc,mheon/runc,rhatdan/runc