ci(lint): setup golangci-lint

Signed-off-by: Matthieu MOREL <matthieu.morel35@gmail.com>

pkg/testutils/netns_linux.go

@@ -24,8 +24,9 @@ import (
 	"sync"
 	"syscall"
 
-	"github.com/containernetworking/plugins/pkg/ns"
 	"golang.org/x/sys/unix"
+
+	"github.com/containernetworking/plugins/pkg/ns"
 )
 
 func getNsRunDir() string {
@@ -49,7 +50,6 @@ func getNsRunDir() string {
 // Creates a new persistent (bind-mounted) network namespace and returns an object
 // representing that namespace, without switching to it.
 func NewNS() (ns.NetNS, error) {
-
 	nsRunDir := getNsRunDir()
 
 	b := make([]byte, 16)
@@ -61,7 +61,7 @@ func NewNS() (ns.NetNS, error) {
 	// Create the directory for mounting network namespaces
 	// This needs to be a shared mountpoint in case it is mounted in to
 	// other namespaces (containers)
-	err = os.MkdirAll(nsRunDir, 0755)
+	err = os.MkdirAll(nsRunDir, 0o755)
 	if err != nil {
 		return nil, err
 	}