Update file names in comments

Signed-off-by: Gilles Peskine <Gilles.Peskine@arm.com>
diff --git a/library/x509_oid.c b/library/x509_oid.c
index d05a36d..1637c1c 100644
--- a/library/x509_oid.c
+++ b/library/x509_oid.c
@@ -1,5 +1,5 @@
 /**
- * \file oid.c
+ * \file x509_oid.c
  *
  * \brief Object Identifier (OID) database
  *
diff --git a/library/x509_oid.h b/library/x509_oid.h
index d4bbd09..5f51367 100644
--- a/library/x509_oid.h
+++ b/library/x509_oid.h
@@ -1,5 +1,5 @@
 /**
- * \file oid.h
+ * \file x509_oid.h
  *
  * \brief Object Identifier (OID) database
  */
@@ -7,8 +7,8 @@
  *  Copyright The Mbed TLS Contributors
  *  SPDX-License-Identifier: Apache-2.0 OR GPL-2.0-or-later
  */
-#ifndef MBEDTLS_OID_H
-#define MBEDTLS_OID_H
+#ifndef MBEDTLS_X509_OID_H
+#define MBEDTLS_X509_OID_H
 #include "mbedtls/private_access.h"
 
 #include "tf-psa-crypto/build_info.h"
@@ -692,4 +692,4 @@
 }
 #endif
 
-#endif /* oid.h */
+#endif /* x509_oid.h */