src/xdisp.c: Remove unused parameters.

src/xdisp.c: Remove unused parameters.

* dispextern.h (move_it_by_lines):
* xdisp.c (move_it_by_lines): Remove parameter `need_y_p', unused
  since 2000-12-29T14:24:09Z!gerd@gnu.org.  All callers changed.
  (message_log_check_duplicate): Remove parameters `prev_bol' and
  `this_bol', unused since 1998-01-01T02:27:27Z!rms@gnu.org.  All callers changed.
  (redisplay_internal): Remove parameter `preserve_echo_area',
  unused since 1999-07-21T21:43:52Z!gerd@gnu.org.  All callers changed.
* indent.c (Fvertical_motion):
* window.c (window_scroll_pixel_based, Frecenter):
  Don't pass `need_y_p' to `move_it_by_lines'.