Unify generic errors to PSA errors

Signed-off-by: Felix Conway <felix.conway@arm.com>
diff --git a/include/mbedtls/x509_csr.h b/include/mbedtls/x509_csr.h
index b115394..60a553f 100644
--- a/include/mbedtls/x509_csr.h
+++ b/include/mbedtls/x509_csr.h
@@ -263,7 +263,7 @@
  * \param ctx       CSR context to use
  * \param key_usage key usage flags to set
  *
- * \return          0 if successful, or MBEDTLS_ERR_X509_ALLOC_FAILED
+ * \return          0 if successful, or #PSA_ERROR_INSUFFICIENT_MEMORY
  *
  * \note            The <code>decipherOnly</code> flag from the Key Usage
  *                  extension is represented by bit 8 (i.e.
@@ -281,7 +281,7 @@
  * \param ctx       CSR context to use
  * \param san_list  List of SAN values
  *
- * \return          0 if successful, or MBEDTLS_ERR_X509_ALLOC_FAILED
+ * \return          0 if successful, or #PSA_ERROR_INSUFFICIENT_MEMORY
  *
  * \note            Only "dnsName", "uniformResourceIdentifier" and "otherName",
  *                  as defined in RFC 5280, are supported.
@@ -296,7 +296,7 @@
  * \param ctx           CSR context to use
  * \param ns_cert_type  Netscape Cert Type flags to set
  *
- * \return          0 if successful, or MBEDTLS_ERR_X509_ALLOC_FAILED
+ * \return          0 if successful, or #PSA_ERROR_INSUFFICIENT_MEMORY
  */
 int mbedtls_x509write_csr_set_ns_cert_type(mbedtls_x509write_csr *ctx,
                                            unsigned char ns_cert_type);
@@ -312,7 +312,7 @@
  * \param val       value of the extension OCTET STRING
  * \param val_len   length of the value data
  *
- * \return          0 if successful, or a MBEDTLS_ERR_X509_ALLOC_FAILED
+ * \return          0 if successful, or a #PSA_ERROR_INSUFFICIENT_MEMORY
  */
 int mbedtls_x509write_csr_set_extension(mbedtls_x509write_csr *ctx,
                                         const char *oid, size_t oid_len,