libpod: run conmon from the persist directory

conmon creates a "oom" file inside the current working directory when
an OOM event happens in the cgroup.  Run conmon from the persist
directory so it doesn't leak files in the directory where Podman runs.

Signed-off-by: Giuseppe Scrivano <[email protected]>

libpod/oci_conmon_common.go

@@ -1197,6 +1197,7 @@ func (r *ConmonOCIRuntime) createOCIContainer(ctr *Container, restoreOptions *Co
 	cmd.Stdin = os.Stdin
 	cmd.Stdout = os.Stdout
 	cmd.Stderr = os.Stderr
+	cmd.Dir = persistDir
 	if ctr.Terminal() {
 		cmd.Stderr = &stderrBuf
 	}