staging: rtl8188eu: os_dep: usb_intf.c: Cleaning up unnecessary code

Removes unnecessary code that does not do anything useful.

This was partly found using a static code analysis program called cppcheck.

Signed-off-by: Rickard Strandqvist <rickard_strandqvist@spectrumdigital.se>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>