The pointer argument of macro need to be taken out once first, and then
use the new pointer in the macro body.

In kernel/trace/trace.c, get_user(ch, ubuf++) causes the unexpected
increment after expand the macro.
Signed-off-by: Zong Li <zong@andestech.com>
Acked-by: Greentime Hu <greentime@andestech.com>
Signed-off-by: Greentime Hu <greentime@andestech.com>