Replaces `bzero()` with `memset()`, which is more widely portable.

The Windows Envoy build does not like `bzero()`.

Protected by no functional change, not protected.

PiperOrigin-RevId: 597683065
diff --git a/quiche/quic/load_balancer/load_balancer_config.cc b/quiche/quic/load_balancer/load_balancer_config.cc
index 00dd5de..726d07e 100644
--- a/quiche/quic/load_balancer/load_balancer_config.cc
+++ b/quiche/quic/load_balancer/load_balancer_config.cc
@@ -213,8 +213,8 @@
   } else {
     is_length_odd = false;
   }
-  bzero(left, kLoadBalancerBlockSize);
-  bzero(right, kLoadBalancerBlockSize);
+  memset(left, 0, kLoadBalancerBlockSize);
+  memset(right, 0, kLoadBalancerBlockSize);
   // The first byte is the plaintext/ciphertext length, the second byte will be
   // the index of the pass. Half the plaintext or ciphertext follows.
   left[0] = plaintext_len();