rtl8192e: Fixing checkpatch errors

This patch fixes the following checkpatch errors from rtllib_endianfree.h:
 - ERROR: Macros with complex values should be enclosed in parenthesis

Signed-off-by: Andreas Frembs <andreas.frembs@studium.uni-erlangen.de>
Signed-off-by: Matthias Schoepe <matthias.schoepe@studium.uni-erlangen.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>