status: add comments for ahead_behind_flags in serialization

The "ahead_behind_flags" field of "struct wt_status" does not
need to be stored in the serialization cache file, since it is
a display property.  Update the code comments in both serialize
and deserialize to reflect that.

Signed-off-by: Jeff Hostetler <jeffhost@microsoft.com>

wt-status-deserialize.c

@@ -536,6 +536,7 @@ static int wt_deserialize_fd(const struct wt_status *cmd_s, struct wt_status *de
 	/* show_branch */
 	/* show_stash */
 	/* hints */
+	/* ahead_behind_flags */
 	if (cmd_s->detect_rename != des_s->detect_rename) {
 		trace_printf_key(&trace_deserialize, "reject: detect_rename");
 		return DESERIALIZE_ERR;

wt-status-serialize.c

@@ -48,6 +48,7 @@ static void wt_serialize_v1_header(struct wt_status *s, int fd)
 	/* show_branch */
 	/* show_stash */
 	packet_write_fmt(fd, "hints %d\n", s->hints);
+	/* ahead_behind_flags */
 	packet_write_fmt(fd, "detect_rename %d\n", s->detect_rename);
 	packet_write_fmt(fd, "rename_score %d\n", s->rename_score);
 	packet_write_fmt(fd, "rename_limit %d\n", s->rename_limit);