Get rid of UnixSocket::BlockingMode.

This is easy to get wrong if we forget to specify the mode for Send,
so there is no reason to keep this.

Bug: 117139237

Change-Id: Ib515c1a518762f8fcecf93e065e639ce72cc1db4
diff --git a/test/producer_socket_fuzzer.cc b/test/producer_socket_fuzzer.cc
index 46904df..5f7bc3a 100644
--- a/test/producer_socket_fuzzer.cc
+++ b/test/producer_socket_fuzzer.cc
@@ -37,8 +37,7 @@
 
   void OnConnect(base::UnixSocket* self, bool connected) override {
     PERFETTO_CHECK(connected && self->is_connected());
-    self->Send(data_, size_, self->fd(),
-               base::UnixSocket::BlockingMode::kBlocking);
+    self->Send(data_, size_, self->fd());
     data_sent_();
   }