Really small correction.
This anti-example in the Closures section is supposed to fail because of a borrow, but it was failing at the type inference because of insufficient type information.
This makes it fail for the expected reason.
This commit is an attempt to standardize the use of punctuation and
formatting in "The Rust Programming Language" as discussed in #19823.
- Convert bold text to italicized textcwhen referring to terminology.
- Convert single-quoted text to italicized or double-quoted text,
depending on context.
- Use double quotes only in the case of scare quotes or quotations.
