No __reboot() symbol in Ubuntu.
Not sure how to maintain Android compatibility here; may not need to.
diff --git a/reboot.c b/reboot.c
index 89c9fce..0c66d48 100644
--- a/reboot.c
+++ b/reboot.c
@@ -47,9 +47,9 @@
         sync();
 
     if(poweroff)
-        ret = __reboot(LINUX_REBOOT_MAGIC1, LINUX_REBOOT_MAGIC2, LINUX_REBOOT_CMD_POWER_OFF, NULL);
+        ret = reboot(LINUX_REBOOT_MAGIC1, LINUX_REBOOT_MAGIC2, LINUX_REBOOT_CMD_POWER_OFF, NULL);
     else if(argc > optind)
-        ret = __reboot(LINUX_REBOOT_MAGIC1, LINUX_REBOOT_MAGIC2, LINUX_REBOOT_CMD_RESTART2, argv[optind]);
+        ret = reboot(LINUX_REBOOT_MAGIC1, LINUX_REBOOT_MAGIC2, LINUX_REBOOT_CMD_RESTART2, argv[optind]);
     else
         ret = reboot(RB_AUTOBOOT);
     if(ret < 0) {