Make mbedtls_sa_ecp_load_public_part return psa_status_t

Signed-off-by: Paul Elliott <paul.elliott@arm.com>
diff --git a/library/psa_crypto_ecp.h b/library/psa_crypto_ecp.h
index 8b567fe..c7ef534 100644
--- a/library/psa_crypto_ecp.h
+++ b/library/psa_crypto_ecp.h
@@ -52,10 +52,10 @@
  *
  * \param ecp               The ECP context to load the public part for.
  *
- * \return 0 on success, otherwise an MPI error.
+ * \return PSA_SUCCESS on success, otherwise an MPI error.
  */
 
-int mbedtls_psa_ecp_load_public_part(mbedtls_ecp_keypair *ecp);
+psa_status_t mbedtls_psa_ecp_load_public_part(mbedtls_ecp_keypair *ecp);
 
 /** Import an ECP key in binary format.
  *