Fix minor linting issue (#1103)

As the CI couldn’t run on forked repo due to env variable capture, fix
now this linting issue.

internal/adsysservice/adsysservice.go

@@ -188,7 +188,7 @@ func WithWinbindConfig(c winbind.Config) func(o *options) error {
 	}
 }
 
-// WithGpoListTimeout specifies the timeout for the gpo list
+// WithGpoListTimeout specifies the timeout for the gpo list.
 func WithGpoListTimeout(t time.Duration) func(o *options) error {
 	return func(o *options) error {
 		o.gpoListTimeout = t