Fix typo

Author: davidanthoff

src/loadsave.jl

@@ -54,7 +54,7 @@ trying to infer the format from `filename`.
 save(s::Union{AbstractString,IO}, data...; options...) =
     save(query(s), data...; options...)
 
-function save(Union{AbstractString,IO}; options...)
+function save(s::Union{AbstractString,IO}; options...)
     data -> save(s, data; options...)
 end