vim-patch:8.2.3490: superfluous return statements #15978

Problem:    Superfluous return statements.
Solution:   Remove superfluous return statements from void functions.
            (closes vim/vim#8977)
3826c0513b

src/nvim/getchar.c

@@ -293,7 +293,6 @@ static void add_buff(buffheader_T *const buf, const char *const s, ptrdiff_t sle
     buf->bh_curr->b_next = p;
     buf->bh_curr = p;
   }
-  return;
 }
 
 /*