apparmor: localize getting the security context to a few macros

Signed-off-by: John Johansen <john.johansen@canonical.com>
Acked-by: Seth Arnold <seth.arnold@canonical.com>
diff --git a/security/apparmor/lsm.c b/security/apparmor/lsm.c
index 10843aa..2027fdf 100644
--- a/security/apparmor/lsm.c
+++ b/security/apparmor/lsm.c
@@ -48,8 +48,8 @@
  */
 static void apparmor_cred_free(struct cred *cred)
 {
-	aa_free_task_context(cred->security);
-	cred->security = NULL;
+	aa_free_task_context(cred_cxt(cred));
+	cred_cxt(cred) = NULL;
 }
 
 /*
@@ -62,7 +62,7 @@
 	if (!cxt)
 		return -ENOMEM;
 
-	cred->security = cxt;
+	cred_cxt(cred) = cxt;
 	return 0;
 }
 
@@ -77,8 +77,8 @@
 	if (!cxt)
 		return -ENOMEM;
 
-	aa_dup_task_context(cxt, old->security);
-	new->security = cxt;
+	aa_dup_task_context(cxt, cred_cxt(old));
+	cred_cxt(new) = cxt;
 	return 0;
 }
 
@@ -87,8 +87,8 @@
  */
 static void apparmor_cred_transfer(struct cred *new, const struct cred *old)
 {
-	const struct aa_task_cxt *old_cxt = old->security;
-	struct aa_task_cxt *new_cxt = new->security;
+	const struct aa_task_cxt *old_cxt = cred_cxt(old);
+	struct aa_task_cxt *new_cxt = cred_cxt(new);
 
 	aa_dup_task_context(new_cxt, old_cxt);
 }
@@ -507,7 +507,7 @@
 	int error = -ENOENT;
 	/* released below */
 	const struct cred *cred = get_task_cred(task);
-	struct aa_task_cxt *cxt = cred->security;
+	struct aa_task_cxt *cxt = cred_cxt(cred);
 
 	if (strcmp(name, "current") == 0)
 		error = aa_getprocattr(aa_newest_version(cxt->profile),
@@ -880,7 +880,7 @@
 		return -ENOMEM;
 
 	cxt->profile = aa_get_profile(root_ns->unconfined);
-	cred->security = cxt;
+	cred_cxt(cred) = cxt;
 
 	return 0;
 }
@@ -910,8 +910,8 @@
 	error = register_security(&apparmor_ops);
 	if (error) {
 		struct cred *cred = (struct cred *)current->real_cred;
-		aa_free_task_context(cred->security);
-		cred->security = NULL;
+		aa_free_task_context(cred_cxt(cred));
+		cred_cxt(cred) = NULL;
 		AA_ERROR("Unable to register AppArmor\n");
 		goto register_security_out;
 	}