mount debugfs

- cherry-pick of a27863d7ffb4d1915384020ab39834b0c3a05c49
- necessary for systrace

Change-Id: I46c9fc63e8b695a66d57015d3bf9eed46471c493
diff --git a/init.mini-emulator.rc b/init.mini-emulator.rc
index dd13303..147746b 100644
--- a/init.mini-emulator.rc
+++ b/init.mini-emulator.rc
@@ -13,6 +13,8 @@
     symlink /storage/emulated/legacy /storage/sdcard0
     symlink /mnt/shell/emulated/0 /storage/emulated/legacy
 
+    mount debugfs debugfs /sys/kernel/debug
+
 #on fs
 #    setprop ro.crypto.umount_sd false