staging: r8188eu: return an error code in rtw_usb_if1_init

rtw_usb_if1_init returns a pointer that isn't used by the caller. Return
an error code instead. We can then propagate errors from lower-level
functions like ReadAdapterInfo8188EU and fail the initialisation of the
driver with a proper error code.

Tested-by: Philipp Hortmann <philipp.g.hortmann@gmail.com> # Edimax N150
Signed-off-by: Martin Kaiser <martin@kaiser.cx>
Link: https://lore.kernel.org/r/20220730143939.671951-4-martin@kaiser.cx


Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>