Fix some dialyzer errors in yz_dt_extractor.

[seancribbs]

Found by @rzezeski in #250.

[hazen]

No sign of the dialyzer errors which were found in #250

102c102
< ==> before (compile)
---
> ==> after (compile)
131,132d130
< yz_dt_extractor.erl:93: The variable Err can never match since previous clauses completely covered the type #state{}
< yz_dt_extractor.erl:99: The call yz_dt_extractor:extract_map(Name::binary()) breaks the contract (field_path_name()) -> fun(({{binary(),module()},term()},state()) -> state())

👍

[seancribbs]

@javajolt You got your dialyzer woes solved?

[hazen]

yup

[seancribbs]

Thanks for the review!

[hazen]

Thanks for the help!