podcheck.t: Re-enable --add_link

Commit 83ced75 broke the --add_link option to podcheck.t.  Now fixed

t/porting/podcheck.t

@@ -566,7 +566,13 @@ if (($regen + $show_all + $show_counts + $add_link + $cpan_or_deltas ) > 1) {
 
 my $has_input_files = @files;
 
-if ($has_input_files) {
+
+if ($add_link) {
+    if (! $has_input_files) {
+        croak "--add_link requires at least one module or man page reference";
+    }
+}
+elsif ($has_input_files) {
     if ($regen || $show_counts || $do_upstream_cpan || $do_deltas) {
         croak "--regen, --counts, --deltas, and --cpan can't be used since using specific files";
     }
@@ -575,10 +581,6 @@ if ($has_input_files) {
     }
 }
 
-if ($add_link && ! $has_input_files) {
-    croak "--add_link requires at least one module or man page reference";
-}
-
 our %problems;  # potential problems found in this run
 
 package My::Pod::Checker {      # Extend Pod::Checker