Don't log userspace_reboot.started/finished properties from init

Instead they will be logged from system_server. This CL just prepares
grounds for logging CL to land.

Test: adb reboot userspace
Bug: 148767783
Change-Id: Ie9482ef735344ecfb0de8a37785d314a3c0417ff
diff --git a/rootdir/init.rc b/rootdir/init.rc
index 5fbad75..4564d26 100644
--- a/rootdir/init.rc
+++ b/rootdir/init.rc
@@ -1058,4 +1058,4 @@
   trigger boot
 
 on property:sys.boot_completed=1 && property:sys.init.userspace_reboot.in_progress=1
-  finish_userspace_reboot
+  setprop sys.init.userspace_reboot.in_progress ""