Fix a typo in list-register-names command.

It was giving error when process was valid.

llvm-svn: 228299
diff --git a/lldb/tools/lldb-mi/MICmdCmdData.cpp b/lldb/tools/lldb-mi/MICmdCmdData.cpp
index efd8310..b7688d7 100644
--- a/lldb/tools/lldb-mi/MICmdCmdData.cpp
+++ b/lldb/tools/lldb-mi/MICmdCmdData.cpp
@@ -828,7 +828,7 @@
 {
     CMICmnLLDBDebugSessionInfo &rSessionInfo(CMICmnLLDBDebugSessionInfo::Instance());
     lldb::SBProcess sbProcess = rSessionInfo.GetProcess();
-    if (sbProcess.IsValid())
+    if (!sbProcess.IsValid())
     {
         SetError(CMIUtilString::Format(MIRSRC(IDS_CMD_ERR_INVALID_PROCESS), m_cmdData.strMiCmd.c_str()));
         return MIstatus::failure;