Debugger: Remove GdbCommand::callbackName

This was a debugging aid that has not been needed for a while.

Change-Id: Ia79e8e91b6648bdb807836443b01dd325d819640
Reviewed-by: hjk <hjk@theqtcompany.com>

src/plugins/debugger/gdb/remotegdbserveradapter.cpp

@@ -49,7 +49,7 @@
 namespace Debugger {
 namespace Internal {
 
-#define CB(callback) [this](const DebuggerResponse &r) { callback(r); }, STRINGIFY(callback)
+#define CB(callback) [this](const DebuggerResponse &r) { callback(r); }
 
 ///////////////////////////////////////////////////////////////////////
 //