smackfs load append mode fix

Given just how hard it is to find the code that uses MAY_APPEND
it's probably not a big surprise that this went unnoticed for so
long. The Smack rules loading code is incorrectly setting the
MAY_READ bit when MAY_APPEND is requested.
Signed-off-by: NCasey Schaufler <casey@schaufler-ca.com>
Reviewed-by: NJames Morris <jmorris@namei.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

security/smack/smackfs.c

@@ -334,7 +334,7 @@ static ssize_t smk_write_load(struct file *file, const char __user *buf,
 		break;
 	case 'a':
 	case 'A':
-		rule.smk_access |= MAY_READ;
+		rule.smk_access |= MAY_APPEND;
 		break;
 	default:
 		goto out;