Fix a crash in GDBRemoteCommunicationClient::GetSupportedStructuredDataPlugins

The function was attempting to write the reply to the log even if the reply was empty.

llvm-svn: 279513
diff --git a/lldb/source/Plugins/Process/gdb-remote/GDBRemoteCommunicationClient.cpp b/lldb/source/Plugins/Process/gdb-remote/GDBRemoteCommunicationClient.cpp
index 79ff5d1..038ba30 100644
--- a/lldb/source/Plugins/Process/gdb-remote/GDBRemoteCommunicationClient.cpp
+++ b/lldb/source/Plugins/Process/gdb-remote/GDBRemoteCommunicationClient.cpp
@@ -3975,7 +3975,7 @@
                             __FUNCTION__);
         }
 
-        if (log && m_supported_async_json_packets_is_valid)
+        if (log && m_supported_async_json_packets_sp)
         {
             StreamString  stream;
             m_supported_async_json_packets_sp->Dump(stream);