Fix double data type issue in hamming_loss_fn.

Author: Oceania2018

src/TensorFlowNET.Keras/Metrics/metrics_utils.cs

@@ -31,7 +31,7 @@ public static Tensor hamming_loss_fn(Tensor y_true, Tensor y_pred, Tensor thresh
             threshold = tf.reduce_max(y_pred, axis: -1, keepdims: true);
             // make sure [0, 0, 0] doesn't become [1, 1, 1]
             // Use abs(x) > eps, instead of x != 0 to check for zero
-            y_pred = tf.logical_and(y_pred >= threshold, tf.abs(y_pred) > 1e-12);
+            y_pred = tf.logical_and(y_pred >= threshold, tf.abs(y_pred) > 1e-12f);
         }
         else
         {