Type it this way: mount -o rw,remount /system
Ran into the same problem, this worked for me.
Hey sleeplessninja, this did work for me at first, but once I press the triggers they still control the camera and when released begin spinning again. I tried at first just copying the KCM but then copied your 291.kl and redid the process to the same result, anything you could think of? Running shield TV stock rooted with xbox360 wireless dongle
Edit: I'm going to run a logcat of my dongle connecting to make sure I get the same ID/Product as you show here.
edit2: I used dmesg to see buffer when I connected my own dongle, it shows the same as 045e and 0719. I'm going to try overwriting my own 719 with your modified one then changing permissions to 644 via es file manager. rebooted and still no dice. rip me I'm going to bed and using a DS3 tomorrow.