staging:rtl8192u: Remove charData and rename shortData - Style

The union ba_param_set contains the member variable charData which is
unused. The variable has been removed.

Additionally the member variable shortData has been renamed to clear
a checkpatch issue with CamelCase naming.

These are coding style changes which should not impact runtime code
execution.

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