Cleaning up printer

original commit: 80da9872e0b0aad0890988dcead6badeaa5f20dc

collects/datalog/private/pprint.rkt

@@ -7,9 +7,9 @@
 (define (text s) s)
 (define (h-append . ss) (apply string-append ss))
 (define (v-concat/s ss)
-  (apply string-append (add-between ss "\n")))
+  (apply string-append ss))
 (define (v-concat ss)
-  (v-concat/s ss))
+  (apply string-append (add-between ss "\n")))
 (define (apply-infix d ds)
   (add-between ds d))
 (define line "\n")