Revert "init.rc: Create /storage mountpoint so Dalvik can mark as slave in zygotes"

No longer needed as Dalvik no longer marks /storage as slave in zygotes.

This reverts commit 4a8f70d11b225fbf56aca6e494f4de35fc727dc7.

Change-Id: I0bfb86f2cc10ccdc10daa7419ac4d252c8dfbae8