[gtk-doc] mkdb: fix "Negative repeat count does nothing" warning

[Stefan Kost <stefkost src gnome org>]

commit 2f968fede39732677efaac205fb8f1e9ae46d90e
Author: Stefan Sauer <ensonic users sf net>
Date:   Sun Jul 31 21:56:01 2016 +0200

    mkdb: fix "Negative repeat count does nothing" warning
    
    Fixes #769341

 gtkdoc-mkdb.in |    5 ++++-
 1 files changed, 4 insertions(+), 1 deletions(-)
---
diff --git a/gtkdoc-mkdb.in b/gtkdoc-mkdb.in
index ab1ab20..6ee0eba 100755
--- a/gtkdoc-mkdb.in
+++ b/gtkdoc-mkdb.in
@@ -3963,7 +3963,10 @@ sub GetArgs {
                 }
             }
 
-            my $pad1 = " " x (24 - length ($name));
+            my $pad1 = "";
+            if (length ($name) < 24) {
+              $pad1 = " " x (24 - length ($name));
+            }
 
             my $arg_synop = "<row><entry role=\"property_type\">$type_output</entry><entry 
role=\"property_name\"><link linkend=\"$id\">$name</link></entry><entry 
role=\"property_flags\">$flags_string</entry></row>\n";
             my $arg_desc = "<refsect2 id=\"$id\" role=\"property\"><title>The <literal>“$name”</literal> 
$kind</title>\n";