dpkg: Remove redundant check for otherpkg being pkg on file replaces

This check is already covered by comparing if they are part of the same
package set. As the fileslistvalid check needs to be moved just before
the write_filelist_except() call to be able to insert actions into the
loop that get executed on each iteration, this test there would be too
late by then, and keeping it standalone does not make much sense, so
let's just remove it right away to make the refactoring smoother.

src/processarc.c

@@ -1343,7 +1343,7 @@ void process_archive(const char *filename) {
             pkg_name(otherpkg, pnaw_always));
       /* If !fileslistvalid then it's one of the disappeared packages above
        * and we don't bother with it here, clearly. */
-      if (otherpkg == pkg || !otherpkg->clientdata->fileslistvalid)
+      if (!otherpkg->clientdata->fileslistvalid)
         continue;
       /* A pkgset can share files between instances, so there's no point
        * in rewriting the file that's already in place. */