staging: rtl8188eu: while loop replaced by for loop in rtw_restruct_wmm_ie

This patch replaces while loop with for loop, because the initial condition and the increment clearly and briefly defined for this loop.

Signed-off-by: Ivan Safonov <insafonov@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>