Fix minor typos in previous change.

src/alloc.c

@@ -5361,7 +5361,7 @@ mark_object (Lisp_Object arg)
 	  if (po != &buffer_defaults && po != &buffer_local_symbols)
 	    {
 	      struct buffer *b;
-	      for (b = all_buffers; b && b != po; b = b->header.next)
+	      for (b = all_buffers; b && b != po; b = b->header.next.buffer)
 		;
 	      if (b == NULL)
 		abort ();

src/buffer.c

@@ -43,7 +43,7 @@ along with GNU Emacs.  If not, see <http://www.gnu.org/licenses/>.  */
 struct buffer *current_buffer;		/* the current buffer */
 
 /* First buffer in chain of all buffers (in reverse order of creation).
-   Threaded through ->header.next.  */
+   Threaded through ->header.next.buffer.  */
 
 struct buffer *all_buffers;