AppArmor: Fix error returned when a path lookup is disconnected

The returning of -ESATLE when a path lookup fails as disconnected is wrong.
Since AppArmor is rejecting the access return -EACCES instead.

This also fixes a bug in complain (learning) mode where disconnected paths
are denied because -ESTALE errors are not ignored causing failures that
can change application behavior.
Signed-off-by: John Johansen <john.johansen@canonical.com>

security/apparmor/path.c

@@ -137,7 +137,7 @@ static int d_namespace_path(struct path *path, char *buf, int buflen,
 			/* disconnected path, don't return pathname starting
 			 * with '/'
 			 */
-			error = -ESTALE;
+			error = -EACCES;
 			if (*res == '/')
 				*name = res + 1;
 		}