Do not overflow local buffer
Do not overflow local buffer

Do not use full width of buf, as we intend to assign

    buf[num_read] = '\0';

at the end of the buffer, afterwards. In case we have just read full BUF_SIZE,
we will write '\0' to a memory location that is outside of buf. This can be
referred to as CWE-119 although, it seems pretty harmless in this case.

Signed-off-by: Šimon Lukašík <864aa5f8ce9b2222e505367bafa459c4402e2c17@fedoraproject.org>

kubernetes-incubator/ocid,mikebrow/cri-o,rhatdan/cri-o,kubernetes-incubator/cri-o,mikebrow/cri-o,nalind/cri-o,mikebrow/cri-o,kubernetes-incubator/cri-o,rhatdan/cri-o,nalind/cri-o,kubernetes-incubator/cri-o,kubernetes-incubator/ocid,kubernetes-incubator/ocid,mikebrow/cri-o,nalind/cri-o,kubernetes-incubator/cri-o,rhatdan/cri-o,rhatdan/cri-o