staging:rtl8192u: Remove the unused AC_CODING definitions - Style

The AC_CODING definitions are unused in code, so have simply been removed
from source. This is a coding style change and should not impact runtime
code execution.

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