patch 9.1.0077: Unnecessary call to redraw_for_cursorline() in nv_mousescroll()

patch 9.1.0077: Unnecessary call to redraw_for_cursorline() in nv_mousescroll()

Problem:  The call to redraw_for_cursorline() in nv_mousescroll() is
          unnecessary because redraw_for_cursorline() only sets redraw
          type to UPD_VALID, and all code paths in do_mousescroll()
          already set redraw type to at least UPD_VALID.
Solution: Remove call to redraw_for_cursorline() in nv_mousescroll().
          (zeertzjq)

closes: #13979

Signed-off-by: zeertzjq <zeertzjq@outlook.com>
Signed-off-by: Christian Brabandt <cb@256bit.org>