audit: audit_set_auditable defined but not used

after 0590b933 audit_set_auditable() is now only
used by the audit tree code.  If CONFIG_AUDIT_TREE is unset it will be defined
but unused.  This patch simply moves the function inside a CONFIG_AUDIT_TREE
block.

cc1: warnings being treated as errors
/home/acme_unencrypted/git/linux-2.6-tip/kernel/auditsc.c:745: error: ‘audit_set_auditable’ defined but not used
make[2]: *** [kernel/auditsc.o] Error 1
make[1]: *** [kernel] Error 2
make[1]: *** Waiting for unfinished jobs....
Signed-off-by: NEric Paris <eparis@redhat.com>
Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>

kernel/auditsc.c

@@ -329,6 +329,14 @@ static int audit_match_filetype(struct audit_context *ctx, int which)
  */
 
 #ifdef CONFIG_AUDIT_TREE
+static void audit_set_auditable(struct audit_context *ctx)
+{
+	if (!ctx->prio) {
+		ctx->prio = 1;
+		ctx->current_state = AUDIT_RECORD_CONTEXT;
+	}
+}
+
 static int put_tree_ref(struct audit_context *ctx, struct audit_chunk *chunk)
 {
 	struct audit_tree_refs *p = ctx->trees;
@@ -742,14 +750,6 @@ void audit_filter_inodes(struct task_struct *tsk, struct audit_context *ctx)
 	rcu_read_unlock();
 }
 
-static void audit_set_auditable(struct audit_context *ctx)
-{
-	if (!ctx->prio) {
-		ctx->prio = 1;
-		ctx->current_state = AUDIT_RECORD_CONTEXT;
-	}
-}
-
 static inline struct audit_context *audit_get_context(struct task_struct *tsk,
 						      int return_valid,
 						      long return_code)