cgroup2: Don't retry on EINTR

Follow-up from a similar change for cgroup1 package here. Since Go 1.15
the stdlib automatically retries IO on EINTR, and since this package
uses things from go 1.16, all consumers of this pkg should be on > 1.15
making any manual retries on EINTR unnecessary.

Signed-off-by: Danny Canter <danny@dcantah.dev>

cgroup2/manager.go

@@ -144,20 +144,11 @@ func (c *Value) write(path string, perm os.FileMode) error {
 		return ErrInvalidFormat
 	}
 
-	// Retry writes on EINTR; see:
-	//    https://github.com/golang/go/issues/38033
-	for {
-		err := os.WriteFile(
-			filepath.Join(path, c.filename),
-			data,
-			perm,
-		)
-		if err == nil {
-			return nil
-		} else if !errors.Is(err, syscall.EINTR) {
-			return err
-		}
-	}
+	return os.WriteFile(
+		filepath.Join(path, c.filename),
+		data,
+		perm,
+	)
 }
 
 func writeValues(path string, values []Value) error {
@@ -763,7 +754,8 @@ func setDevices(path string, devices []specs.LinuxDeviceCgroup) error {
 // the reason this is necessary is because the "-" character has a special meaning in
 // systemd slice. For example, when creating a slice called "my-group-112233.slice",
 // systemd will create a hierarchy like this:
-//      /sys/fs/cgroup/my.slice/my-group.slice/my-group-112233.slice
+//
+//	/sys/fs/cgroup/my.slice/my-group.slice/my-group-112233.slice
 func getSystemdFullPath(slice, group string) string {
 	return filepath.Join(defaultCgroup2Path, dashesToPath(slice), dashesToPath(group))
 }