audit: make link()/linkat() match "attribute change" predicate

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

include/asm-generic/audit_change_attr.h

@@ -20,3 +20,7 @@ __NR_chown32,
 __NR_fchown32,
 __NR_lchown32,
 #endif
+__NR_link,
+#ifdef __NR_linkat
+__NR_linkat,
+#endif