Bluetooth: Don't detach the native fd before closing the PFD

As per the comment from the detachfd() function description,
it should not detach the fd in case it is trying to close
the parcel file descriptor (PFD).

So removed the detachFd function call from close function.

Change-Id: Id5cf47f9bbf97b1b83038f70c42056b341fba37f
CRs-Fixed: 623164