Fix Subject Key Identifier, Authority Key Identifier entries in oid_x509_ext

Signed-off-by: Przemek Stekiel <przemyslaw.stekiel@mobica.com>
diff --git a/library/oid.c b/library/oid.c
index 06b535f..bbd9f6f 100644
--- a/library/oid.c
+++ b/library/oid.c
@@ -291,15 +291,15 @@
         MBEDTLS_OID_X509_EXT_CERTIFICATE_POLICIES,
     },
     {
-        { ADD_LEN( MBEDTLS_OID_SUBJECT_KEY_IDENTIFIER ), "id-ce-subjectKeyIdentifier",           "Subject Key Identifier" },
+        OID_DESCRIPTOR( MBEDTLS_OID_SUBJECT_KEY_IDENTIFIER, "id-ce-subjectKeyIdentifier",           "Subject Key Identifier" ),
         MBEDTLS_OID_X509_EXT_SUBJECT_KEY_IDENTIFIER,
     },
     {
-        { ADD_LEN( MBEDTLS_OID_AUTHORITY_KEY_IDENTIFIER ), "id-ce-authorityKeyIdentifier",       "Authority Key Identifier" },
+        OID_DESCRIPTOR( MBEDTLS_OID_AUTHORITY_KEY_IDENTIFIER, "id-ce-authorityKeyIdentifier",       "Authority Key Identifier" ),
         MBEDTLS_OID_X509_EXT_AUTHORITY_KEY_IDENTIFIER,
     },
     {
-        { NULL, 0, NULL, NULL },
+        NULL_OID_DESCRIPTOR,
         0,
     },
 };