conmon: Increase buffer size
conmon: Increase buffer size

The buffer is used to read from the stderr/stdout stream, which
can easily be larger than 256 bytes. With a larger buffer we will
do fewer, larger reads, which is more efficient. And 8k more stack
size use is not really a problem.

Signed-off-by: Alexander Larsson <8c32c4b573bb86be9076a894bc9e0dfe2b512e8a@redhat.com>

mheon/cri-o,kubernetes-incubator/ocid,14rcole/cri-o,mheon/cri-o,rhatdan/cri-o,jwhonce/ocid,vbatts/cri-o,mheon/cri-o,vbatts/cri-o,nalind/cri-o,kubernetes-incubator/ocid,14rcole/cri-o,apilloud/cri-o,rhatdan/cri-o,kubernetes-incubator/cri-o,rhatdan/cri-o,14rcole/cri-o,kubernetes-incubator/cri-o,mikebrow/cri-o,apilloud/cri-o,umohnani8/cri-o,14rcole/cri-o,jwhonce/ocid,kubernetes-incubator/cri-o,kubernetes-incubator/ocid,umohnani8/cri-o,mikebrow/cri-o,umohnani8/cri-o,nalind/cri-o,mikebrow/cri-o,nalind/cri-o,jwhonce/ocid,kubernetes-incubator/cri-o,mheon/cri-o,vbatts/cri-o,vbatts/cri-o,apilloud/cri-o,rhatdan/cri-o,mikebrow/cri-o,umohnani8/cri-o