Fix invalid reference to procedure.

dns/types/rr.scm

@@ -9,7 +9,7 @@
   :use-module (dns enum)
   :use-module (dns types)
   :use-module (dns types rr-data)
-  :use-module ((rnrs bytevectors) :select (bytevector?))
+  :use-module ((rnrs bytevectors) :select (bytevector? bytevector-length))
   :re-export (name type class ttl rdata)
   :export (make-dns-rr-data
            dns-rr-data?
@@ -47,6 +47,6 @@
     (u32! (ttl rr))                     ; ttl
     ;; rdlength and rdata
     (if (bytevector? (rdata rr))
-        (do (u16! (rdlength (rdata rr)))
+        (do (u16! (bytevector-length (rdata rr)))
             (bv-copy! (rdata rr)))
         ((get-serializer (type rr)) (rdata rr)))))