staging:rtl8192u: Remove unused CMPK_TX_SET_CONFIG_SIZE - Style

Remove the unused macro CMPK_TX_SET_CONFIG_SIZE. This is a coding style
change which should not impact runtime code execution.

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