Fixed latex2html weirdness for a footnote.

Doc/ext/ext.tex

@@ -1294,8 +1294,8 @@ checking.
 
 The C function calling mechanism guarantees that the argument list
 passed to C functions (\code{args} in the examples) is never
-\NULL{} --- in fact it guarantees that it is always a tuple.%
-\footnote{These guarantees don't hold when you use the ``old'' style
+\NULL{} --- in fact it guarantees that it is always a tuple.\footnote{
+These guarantees don't hold when you use the ``old'' style
 calling convention --- this is still found in much existing code.}
 
 It is a severe error to ever let a \NULL{} pointer ``escape'' to