Remove unused variables, fix compiler warnings

src/Fl_Menu.cxx

@@ -281,7 +281,6 @@ void Fl_Menu_Item::draw(int x, int y, int w, int h, const Fl_Menu_* m,
   l.size    = labelsize_ ? labelsize_ : m ? m->textsize() : FL_NORMAL_SIZE;
   l.color   = labelcolor_ ? labelcolor_ : m ? m->textcolor() : int(FL_FOREGROUND_COLOR);
   if (!active()) l.color = fl_inactive((Fl_Color)l.color);
-  Fl_Color color = m ? m->color() : FL_GRAY;
   if (selected) {
     Fl_Color r = m ? m->selection_color() : FL_SELECTION_COLOR;
     Fl_Boxtype b = m && m->down_box() ? m->down_box() : FL_FLAT_BOX;

src/drivers/WinAPI/Fl_WinAPI_Printer_Driver.cxx

@@ -333,7 +333,7 @@ void Fl_PDF_GDI_File_Surface::end_job(void)
       if (EndDoc (hPr) <= 0) {
         fl_message ("Error in EndDoc() call");
       }
-      int err = DeleteDC (hPr);
+      DeleteDC (hPr);
     }
     hPr = NULL;
   }