preproc: don't macro-expand the argument to %use

Use expand_id() for the argument to %use, instead of expand_smacro().
This really makes more sense for a "naked" argument.  This is a
semantic change, but is unlikely to break any real code.

Signed-off-by: H. Peter Anvin <hpa@zytor.com>
diff --git a/doc/changes.src b/doc/changes.src
index 5c756a1..00b6076 100644
--- a/doc/changes.src
+++ b/doc/changes.src
@@ -14,6 +14,9 @@
 
 \b \c{%pop} can now take an argument, see \k{pushpop}.
 
+\b The argument to \c{%use} is no longer macro-expanded.  Use
+  \c{%[...]} if macro expansion is desired.
+
 
 \S{cl-2.05} Version 2.05