Buggy formatting of long syntax-parse pattern directives

[jackfirth]

fmt turns this code:

(define-syntax-parse-rule (m)
  #:fail-when (string-append "longggggggggggggg" "stringgggggggg")
  "very very very long failure message goes here"
  (void))

Into this:

(define-syntax-parse-rule (m)
  #:fail-when (string-append "longggggggggggggg"
                             "stringgggggggg") "very very very long failure message goes here"
  (void))

Which is not ideal.