USB: usb-storage: fix return values from init functions

This patch (as1242) fixes the return values from the special
init functions in usb-storage.  They are supposed to return 0 for
success, not USB_STOR_TRANSPORT_GOOD.

Signed-off-by: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>