avoid a warning with perl 5.14

diff --git a/tools/doxygen/index_create.pl b/tools/doxygen/index_create.pl
index 9be03ab..b947465 100755 (executable)
--- a/tools/doxygen/index_create.pl
+++ b/tools/doxygen/index_create.pl
@@ -47,7 +47,7 @@ print OUTPUT <<EOF;
 
 EOF
 
-foreach $type qw(define enumeration enumvalue function typedef) {
+foreach $type (qw(define enumeration enumvalue function typedef)) {
     if(defined $database{$type}) {
        print OUTPUT "<h2>$type</h2> \n  <ul>\n";
        foreach $name (sort keys %{$database{$type}}) {