Remove documentation of non-existant function return values.

src/Fl_Scroll.cxx

@@ -128,9 +128,6 @@ void Fl_Scroll::draw_clip(void* v,int X, int Y, int W, int H) {
   You may need to call redraw() to make sure the widget gets updated.
 
   \param[inout] si -- ScrollInfo structure, filled with data
-
-  \returns Structure containing the calculated info.
-
   \see bbox()
 */
 void Fl_Scroll::recalc_scrollbars(ScrollInfo &si) const {

src/Fl_Timeout.cxx

@@ -220,16 +220,13 @@ void Fl_Timeout::make_current() {
   Remove the top-most timeout from the stack of currently running
   timeout callbacks and insert it into the list of free timers.
 
-  This should always return a non-NULL value, otherwise there's a bug
-  in the library. Typical code in the library would look like:
+  Typical code in the library would look like:
   \code
     // The timeout \p Fl_Timeout *t has exired, run its callback
     t->make_current();
     (t->callback)(t->data);
     t->release();
   \endcode
-
-  \return   Fl_Timeout*   current timeout or NULL
 */
 void Fl_Timeout::release() {
   Fl_Timeout *t = current_timeout;