Fix ecdsa.h documentation error

Signed-off-by: Paul Elliott <paul.elliott@arm.com>
diff --git a/include/mbedtls/ecdsa.h b/include/mbedtls/ecdsa.h
index 1741d2c..c5d9701 100644
--- a/include/mbedtls/ecdsa.h
+++ b/include/mbedtls/ecdsa.h
@@ -416,6 +416,8 @@
  *                  initialized restart context.
  *
  * \return          \c 0 on success.
+ * \return          #MBEDTLS_ERR_ECP_IN_PROGRESS if maximum number of
+ *                  operations was reached: see \c mbedtls_ecp_set_max_ops().
  * \return          An \c MBEDTLS_ERR_ECP_XXX or \c MBEDTLS_MPI_XXX
  *                  error code on failure.
  */
@@ -474,8 +476,6 @@
  *                  \c NULL if \p f_rng is \c NULL or doesn't use a context.
  *
  * \return          \c 0 on success.
- * \return          #MBEDTLS_ERR_ECP_IN_PROGRESS if maximum number of
- *                  operations was reached: see \c mbedtls_ecp_set_max_ops().
  * \return          An \c MBEDTLS_ERR_ECP_XXX, \c MBEDTLS_ERR_MPI_XXX or
  *                  \c MBEDTLS_ERR_ASN1_XXX error code on failure.
  */