staging:rtl8192u: Remove unused union QOS_INFO_FIELD - Style

The union QOS_INFO_FIELD is unused in code so has been removed from source.
This change is a coding style change so should have no impact on runtime
code execution.

Signed-off-by: John Whitmore <johnfwhitmore@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>