dpkg-deb: Parse control file into available structure

This unconfuses the code to make it clear we are not dealing with
installed package information. It's also needed as part of the
infrastructure changes for multiarch support.

dpkg-deb/info.c

@@ -258,8 +258,9 @@ void do_showinfo(const char* const* argv) {
 
   info_prepare(&argv,&debar,&directory,1);
 
-  parsedb(CONTROLFILE, pdb_ignorefiles, &pkg, NULL, NULL);
-  pkg_format_show(fmt, pkg, &pkg->installed);
+  parsedb(CONTROLFILE, pdb_recordavailable | pdb_rejectstatus | pdb_ignorefiles,
+          &pkg, NULL, NULL);
+  pkg_format_show(fmt, pkg, &pkg->available);
 }