Let errors occcur when copying the DPU CNI

It is most likely that we will in the future include a command line
argument for the CNI path since different cluster types will have
different CNI locations.

For now remove the check for "writeable" and simplify the code to just
attempt to copy and make executable.

The writeable code also had a bug where it would check for the file and
not the directory.

Signed-off-by: William Zhao <wizhao@redhat.com>

daemon/main.go

@@ -10,7 +10,6 @@ import (
 	deviceplugin "github.com/openshift/dpu-operator/daemon/device-plugin"
 	"github.com/openshift/dpu-operator/daemon/plugin"
 	"go.uber.org/zap/zapcore"
-	"golang.org/x/sys/unix"
 
 	ctrl "sigs.k8s.io/controller-runtime"
 	"sigs.k8s.io/controller-runtime/pkg/log/zap"
@@ -81,21 +80,12 @@ func makeExecutable(file string) error {
 	return nil
 }
 
-func writable(path string) bool {
-	return unix.Access(path, unix.W_OK) == nil
-}
-
 func prepareCni(path string) error {
-	// Some cluster node environments do not allow certain
-	// directories to be writeable. (e.g. RHCOS systems)
-	if writable(path) {
-		err := copyFile("/dpu-cni", path)
-		if err != nil {
-			return err
-		}
-		return makeExecutable(path)
+	err := copyFile("/dpu-cni", path)
+	if err != nil {
+		return err
 	}
-	return nil
+	return makeExecutable(path)
 }
 
 func main() {
@@ -121,12 +111,12 @@ func main() {
 	err = prepareCni("/var/lib/cni/bin/dpu-cni")
 	if err != nil {
 		log.Error(err, "Failed to prepare CNI binary in /var/lib")
-		return
+		/* Don't return on error for now */
 	}
 	err = prepareCni("/opt/cni/bin/dpu-cni")
 	if err != nil {
 		log.Error(err, "Failed to prepare CNI binary in /opt")
-		return
+		/* Don't return on error for now */
 	}
 
 	dpuMode, err = isDpuMode(mode)