Fix MBEDTLS_PRIVATE wrapping in the library's headers.

Signed-off-by: Mateusz Starzyk <mateusz.starzyk@mobica.com>
diff --git a/include/mbedtls/ecdsa.h b/include/mbedtls/ecdsa.h
index 525de5d..cf063a0 100644
--- a/include/mbedtls/ecdsa.h
+++ b/include/mbedtls/ecdsa.h
@@ -107,12 +107,12 @@
  */
 typedef struct
 {
-    mbedtls_ecp_restart_ctx ecp;        /*!<  base context for ECP restart and
+    mbedtls_ecp_restart_ctx MBEDTLS_PRIVATE(ecp);        /*!<  base context for ECP restart and
                                               shared administrative info    */
-    mbedtls_ecdsa_restart_ver_ctx *ver; /*!<  ecdsa_verify() sub-context    */
-    mbedtls_ecdsa_restart_sig_ctx *sig; /*!<  ecdsa_sign() sub-context      */
+    mbedtls_ecdsa_restart_ver_ctx *MBEDTLS_PRIVATE(ver); /*!<  ecdsa_verify() sub-context    */
+    mbedtls_ecdsa_restart_sig_ctx *MBEDTLS_PRIVATE(sig); /*!<  ecdsa_sign() sub-context      */
 #if defined(MBEDTLS_ECDSA_DETERMINISTIC)
-    mbedtls_ecdsa_restart_det_ctx *det; /*!<  ecdsa_sign_det() sub-context  */
+    mbedtls_ecdsa_restart_det_ctx *MBEDTLS_PRIVATE(det); /*!<  ecdsa_sign_det() sub-context  */
 #endif
 } mbedtls_ecdsa_restart_ctx;