Staging: rtl8188eu: Remove unneeded return statement

This patch removes unnecessary return statement from a void
function and hence make it more compatible.

This issue is identified by checkpatch.pl

Signed-off-by: Somya Anand <somyaanand214@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>