Fixed error handling
Fixed error handling

.eof() can return Err, so do not try to unwrap() it unconditionally.

Also, check result of .parse_whitespaces(), and report, if there is any
errors.

(thanks, @nixpulvis)

bolinfest/serde-jsonrc,PaulGrandperrin/json,serde-rs/json,google/serde_json_lenient