rc.shutdown: print a newline before watchdog timeout message

Previously the watchdog timeout message was appended to the last entry
in the "Waiting for PIDS" list, resulting in a message like

    Waiting for PIDS: 31299 31296 90201 9020090 second watchdog timeout
    expired. Shutdown terminated.

Print a newline to separate the watchdog timeout message.  Also perform
the kill before logging or echoing the message.

PR:		241072
MFC after:	1 month
Sponsored by:	The FreeBSD Foundation

libexec/rc/rc.shutdown

@@ -69,12 +69,13 @@ _rcshutdown_watchdog=
 if [ -n "$rcshutdown_timeout" ]; then
 	debug "Initiating watchdog timer."
 	sleep $rcshutdown_timeout && (
+		kill -KILL $$ >/dev/null 2>&1
 		_msg="$rcshutdown_timeout second watchdog"
 		_msg="$_msg timeout expired. Shutdown terminated."
 		logger -t rc.shutdown "$_msg"
+		echo
 		echo "$_msg"
 		date
-		kill -KILL $$ >/dev/null 2>&1
 	) &
 	_rcshutdown_watchdog=$!
 fi