staging: rtl8188eu: make rtw_usb_if1_init return a status

Return an error status instead of the struct adapter that was allocated
and filled. This is more useful for the probe function, who calls
rtw_usb_if1_init.

Signed-off-by: Martin Kaiser <martin@kaiser.cx>
Link: https://lore.kernel.org/r/20210407170531.29356-10-martin@kaiser.cx


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