libbb: introduce and use msleep()

function                                             old     new   delta
msleep                                                 -      45     +45
watchdog_main                                        271     266      -5
common_traceroute_main                              3546    3530     -16
beep_main                                            277     248     -29
------------------------------------------------------------------------------
(add/remove: 1/0 grow/shrink: 0/3 up/down: 45/-50)             Total: -5 bytes

Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
diff --git a/miscutils/watchdog.c b/miscutils/watchdog.c
index 8c8d721..971b777 100644
--- a/miscutils/watchdog.c
+++ b/miscutils/watchdog.c
@@ -143,7 +143,7 @@
 		 * as the counter value is undefined at this point -- PFM
 		 */
 		write(3, "", 1); /* write zero byte */
-		usleep(stimer_duration * 1000L);
+		msleep(stimer_duration);
 	}
 	return EXIT_SUCCESS; /* - not reached, but gcc 4.2.1 is too dumb! */
 }