Rename class_destroy to avoid namespace conflicts.

We're seeing increasing namespace conflicts between the global
class_destroy() function declared in linux/device.h, and the private
function in the SELinux core code.  This patch renames the SELinux
function to cls_destroy() to avoid this conflict.

Acked-by: Stephen Smalley <sds@tycho.nsa.gov>
Signed-off-by: James Morris <jmorris@namei.org>
diff --git a/security/selinux/ss/policydb.c b/security/selinux/ss/policydb.c
index ba48961..cd79c63 100644
--- a/security/selinux/ss/policydb.c
+++ b/security/selinux/ss/policydb.c
@@ -468,7 +468,7 @@
 	return 0;
 }
 
-static int class_destroy(void *key, void *datum, void *p)
+static int cls_destroy(void *key, void *datum, void *p)
 {
 	struct class_datum *cladatum;
 	struct constraint_node *constraint, *ctemp;
@@ -566,7 +566,7 @@
 static int (*destroy_f[SYM_NUM]) (void *key, void *datum, void *datap) =
 {
 	common_destroy,
-	class_destroy,
+	cls_destroy,
 	role_destroy,
 	type_destroy,
 	user_destroy,
@@ -1124,7 +1124,7 @@
 out:
 	return rc;
 bad:
-	class_destroy(key, cladatum, NULL);
+	cls_destroy(key, cladatum, NULL);
 	goto out;
 }