Fix some duplication on the compare page

For the new and removed package sections.

guix-data-service/comparison.scm

@@ -127,17 +127,19 @@ ORDER BY base_packages.name DESC, base_packages.version, target_packages.name, t
 
 (define (package-data-vhashes->new-packages base-packages-vhash target-packages-vhash)
   (vlist->list
+   (package-data-vhash->package-name-and-version-vhash
     (vlist-filter (match-lambda
                     ((name . details)
                      (not (vhash-assoc name base-packages-vhash))))
-                 target-packages-vhash)))
+                  target-packages-vhash))))
 
 (define (package-data-vhashes->removed-packages base-packages-vhash target-packages-vhash)
   (vlist->list
+   (package-data-vhash->package-name-and-version-vhash
     (vlist-filter (match-lambda
                     ((name . details)
                      (not (vhash-assoc name target-packages-vhash))))
-                 base-packages-vhash)))
+                  base-packages-vhash))))
 
 (define (package-data-vhash->package-versions-vhash package-data-vhash)
   (define (system-and-target<? a b)

guix-data-service/web/view/html.scm

@@ -591,7 +591,7 @@
               (tbody
                ,@(map
                   (match-lambda
-                    ((name version rest ...)
+                    (((name . version) metadata)
                      `(tr
                        (td ,name)
                        (td ,version))))
@@ -610,7 +610,7 @@
               (tbody
                ,@(map
                   (match-lambda
-                    ((name version rest ...)
+                    (((name . version) metadata)
                      `(tr
                        (td ,name)
                        (td ,version))))