staging: r8188eu: Remove unnecessary ret variable in rtw_drv_init()

staging: r8188eu: Remove unnecessary ret variable in rtw_drv_init()

ret is unnecessary as both error paths set the same error code so just
return that directly.

Suggested-by: Fabio M. De Francesco <fmdefrancesco@gmail.com>
Reviewed-by: Fabio M. De Francesco <fmdefrancesco@gmail.com>
Acked-by: Phillip Potter <phil@philpotter.co.uk>
Signed-off-by: Nathan Chancellor <nathan@kernel.org>
Link: https://lore.kernel.org/r/20210813201418.4018631-1-nathan@kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>