staging: rtl8188eu: remove unnecessary initializations

The local variables backup_index, backup_counter and backup_time
in rtw_reset_securitypriv() are all asigned before their uses, so
initialization to zero is not necessary.

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