dpkg: Make pkg_files_add_file() static

src/filesdb.c

@@ -122,7 +122,7 @@ pkg_files_blank(struct pkginfo *pkg)
   pkg->clientdata->files = NULL;
 }
 
-struct fileinlist **
+static struct fileinlist **
 pkg_files_add_file(struct pkginfo *pkg, const char *filename,
                    enum fnnflags flags, struct fileinlist **file_tail)
 {