staging: r8188eu: remove padapter from struct led_priv

staging: r8188eu: remove padapter from struct led_priv

The only struct led_priv that's used in the r8188eu driver in embedded in
the driver's global struct adapter. We can use container_of to access the
"outer" structure, there's no need to store a pointer to it.

Signed-off-by: Martin Kaiser <martin@kaiser.cx>
Tested-by: Philipp Hortmann <philipp.g.hortmann@gmail.com> # Edimax N150
Link: https://lore.kernel.org/r/20221015151115.232095-9-martin@kaiser.cx
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>