Allow comments which will not show up in the ChangeLog

* scripts/gitlog-to-changelog: Ignore lines after a "--" line.

--
The first line with two dashes at the start of a line (optionally
followed by white space) stops copying the commit log lines to the
ChangeLog entry in "make dist".  This is useful to allow adding
comments to the log which are not useful in a ChangeLog.

scripts/gitlog-to-changelog

@@ -281,6 +281,15 @@ sub parse_amend_file($)
       @line = grep !/^Signed-off-by: .*>$/, @line;
       @line = grep !/^Co-authored-by: /, @line;
 
+      # Remove everything after a line with 2 dashes at the beginning.
+      my @tmpline;
+      foreach (@line)
+	{
+	  last if /^--\s*$/;
+          push @tmpline,$_;
+        }
+      @line = @tmpline;
+
       # Remove leading and trailing blank lines.
       if (@line)
         {