USB: android: Allow multiple luns creation during init

The current code assumes that there is only one lun created
during init. If more luns are created during init, the dynamic
luns creation is failing due to kobjects duplication.

Change-Id: Ic8003c4c76545cbe19705345a58f25ceea83b3db
Signed-off-by: Pavankumar Kondeti <pkondeti@codeaurora.org>