Fix unused variables warnings in default + stream cipher only build

Signed-off-by: Przemek Stekiel <przemyslaw.stekiel@mobica.com>
diff --git a/library/psa_crypto.c b/library/psa_crypto.c
index 4a0bd83..e45b5d7 100644
--- a/library/psa_crypto.c
+++ b/library/psa_crypto.c
@@ -3592,6 +3592,7 @@
             break;
 #endif /* PSA_WANT_ALG_CHACHA20_POLY1305 */
         default:
+            (void) nonce_length;
             return( PSA_ERROR_NOT_SUPPORTED );
     }
 
diff --git a/library/ssl_msg.c b/library/ssl_msg.c
index dbef29b..06194bd 100644
--- a/library/ssl_msg.c
+++ b/library/ssl_msg.c
@@ -1124,7 +1124,9 @@
                              mbedtls_ssl_transform *transform,
                              mbedtls_record *rec )
 {
+#if defined(MBEDTLS_SSL_SOME_SUITES_USE_CBC) || defined(MBEDTLS_CIPHER_MODE_AEAD)
     size_t olen;
+#endif /* MBEDTLS_SSL_SOME_SUITES_USE_CBC || MBEDTLS_CIPHER_MODE_AEAD */
     mbedtls_ssl_mode_t ssl_mode;
     int ret;