Squash a couple of warnings in example-deconstructor-alt

example-deconstructor-alt.c: In function ‘main’:
example-deconstructor-alt.c:649:51: warning:
  comparison between ‘yaml_sequence_style_t {aka enum yaml_sequence_style_e}’
  and ‘enum yaml_mapping_style_e’ [-Wenum-compare]

example-deconstructor-alt.c:650:36: warning:
  comparison between ‘yaml_sequence_style_t {aka enum yaml_sequence_style_e}’
  and ‘enum yaml_mapping_style_e’ [-Wenum-compare]