ping: add -w, -W support (James Simmons <jsimmons AT infradead.org>)

function                                             old     new   delta
print_stats_and_exit                                   -     282    +282
sendping_tail                                        151     231     +80
packed_usage                                       23976   24054     +78
ping_main                                            401     412     +11
arm_ioctl                                             13      20      +7
pingstats                                            259       -    -259
------------------------------------------------------------------------------
(add/remove: 1/1 grow/shrink: 4/0 up/down: 458/-259)          Total: 199 bytes

diff --git a/include/usage.h b/include/usage.h
index e007acd..142d7c2 100644
--- a/include/usage.h
+++ b/include/usage.h
@@ -2935,6 +2935,10 @@
      "\n	-c CNT		Send only CNT pings" \
      "\n	-s SIZE		Send SIZE data bytes in packets (default=56)" \
      "\n	-I iface/IP	Use interface or IP address as source" \
+     "\n	-W timeout	Seconds to wait for the first response (default:10)" \
+     "\n			(after all -c CNT packets are sent)" \
+     "\n	-w deadline	Seconds until ping exits (default:infinite)" \
+     "\n			(can exit earlier with -c CNT)" \
      "\n	-q		Quiet, only displays output at start" \
      "\n			and when finished" \