VariableCommentSniff doesn't recognize multiple types

If a property can have multiple data types you can declare this by separating the different types with a pipe:

/**
 * The database log.
 *
 * @var \Drupal\rdf_entity\Database\Driver\sparql\Log|null
 */
protected $log;

Currently the VariableCommentSniff doesn't account for this and throws this false positive:

Expected "\Drupal\rdf_entity\Database\Driver\sparql\Lognull" but found "\Drupal\rdf_entity\Database\Driver\sparql\Log|null" for @var tag in member variable comment