staging: r8188eu: remove return from void functions

Remove return from void functions to clear checkpatch warnings.

WARNING: void function return statements are not generally useful

Signed-off-by: Michael Straube <straube.linux@gmail.com>
Link: https://lore.kernel.org/r/20210801210354.25218-1-straube.linux@gmail.com


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