mount in /data/local/userinit.sh is not working I want to map /sdcard/DCIM to /storage/sdcard1/DCIM
using CM 12.1 on a I9100

I wrote those few lines to /data/local/userinit.sh:

#!/system/bin/sh
log -p i -t userinit "userinit start";
mount -o bind /storage/sdcard1/DCIM /sdcard/DCIM;
log -p i -t userinit "userinit end";


If I execute it the script via adb shell the folder gets mapped perfectly.
But if I reboot the device the folder is not mapped.
In the log I cloud see the userinit start and the userinit end so userinit.sh is called during startup.

I also tried

su root mount -o bind /storage/sdcard1/DCIM /sdcard/DCIM;


Any suggestions?
Found a workaround:
init.d script invocation by app

https://play.google.com/store/apps/details?id=com.ryosoftware.initd