recovery: fix rebooting

Change I84c0513acb549720cb0e8c9fcbda0050f5c396f5 moved reboot
functionality into init but did not update the recovery partition; so
"adb reboot" and /system/bin/reboot in recovery are both broken.

Change-Id: Ie2d14627a686ffb5064256b6c399723636dff116
diff --git a/recovery.cpp b/recovery.cpp
index 654a665..b783393 100644
--- a/recovery.cpp
+++ b/recovery.cpp
@@ -1062,6 +1062,6 @@
     // Otherwise, get ready to boot the main system...
     finish_recovery(send_intent);
     ui->Print("Rebooting...\n");
-    android_reboot(ANDROID_RB_RESTART, 0, 0);
+    property_set(ANDROID_RB_PROPERTY, "");
     return EXIT_SUCCESS;
 }