ntpd: add -w "watch" option, useful for debugging to look at our own data

Also fixed a small buglet discovered using -w

function                                             old     new   delta
recv_and_process_peer_pkt                            895     944     +49
select_and_cluster                                  1132    1150     +18
packed_usage                                       26769   26767      -2

Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
diff --git a/include/usage.h b/include/usage.h
index 9f4c448..5a25241 100644
--- a/include/usage.h
+++ b/include/usage.h
@@ -3223,7 +3223,7 @@
        "Address:    127.0.0.1\n"
 
 #define ntpd_trivial_usage \
-	"[-dngql] [-p PEER]..."
+	"[-dnqwl] [-p PEER]..."
 #define ntpd_full_usage "\n\n" \
        "NTP client/server\n" \
      "\nOptions:" \
@@ -3233,6 +3233,7 @@
 /* -N exists for mostly compat reasons, thus not essential to inform */ \
 /* the user that it exists: user may use nice as well */ \
 /*   "\n	-N	Run at high priority" */ \
+     "\n	-w	Do not set time (used to look at peer data)" \
      "\n	-l	Run as server on port 123" \
      "\n	-p PEER	Obtain time from PEER (may be repeated)" \