usb: host: ehci-tegra: Fix oops in error cleanup

The cleanup path checks whether the transceiver was properly initialized
using IS_ERR(). However it can also happen that the cleanup path is run
before the transceiver was initialized (or the operating mode isn't set
to TEGRA_USB_OTG) and is therefore NULL. Add a separate label for error
unwinding and initialize the transceiver field to ERR_PTR(-ENODEV) when
the operating mode isn't TEGRA_USB_OTG to allow for consistent checking.

Signed-off-by: Thierry Reding <thierry@gilfi.de>
Acked-by: Stephen Warren <swarren@nvidia.com>
Acked-by: Venu Byravarasu <vbyravarasu@nvidia.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>