staging: rtl8188eu: remove rtw_android_set_block()

The function rtw_android_set_block() just returns zero. The only user
is the function rtw_android_priv_cmd(). The variable bytes_written is
initialized to zero and not changed before the use of
rtw_android_set_block(). Remove rtw_android_set_block() and it's only
use.

Signed-off-by: Michael Straube <straube.linux@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>