Remove duplicate declarations.

Remove duplicate declarations.

* lib-src/ebrowse.c (usage, version, mark_virtual)
* src/alloc.c (lisp_malloc)
* src/buffer.c (set_buffer_internal, set_buffer_internal_1)
* src/charset.h (emacs_mule_charset)
* src/dispextern.h (inhibit_free_realized_faces, redraw_frame)
  (redraw_garbaged_frames, scroll_cost, update_frame, scrolling)
  (bitch_at_user)
* src/lisp.h (Fcheck_coding_system, Fget_text_property)
  (Qfunction, Qcompletion_ignore_case, QCwidth, QCsize)