Only generate HTML for log files passed on the command line.

With the make bits already in place, this means that make retest
creates HTML for only the retested tests.

test/make-html.pl

@@ -45,7 +45,9 @@ my $tests = {};
 
 my $teststats = {};
 
-foreach (<*.log>) {
+if ($#ARGV >= 0) { @files = @ARGV; } else { @files = <*.log>; }
+
+foreach (<@files>) {
   (open LOG, "$_") || next;
   while (<LOG>) {
     next unless /^TEST: (.*) TARGET: (.*) FORMAT: (.*) OFFSET: (.*) RESULT: (.*)$/;