Remove an unused variable.

Found using Clang's static analyzer.

Modules/_tkinter.c

@@ -2049,7 +2049,7 @@ static int
 PythonCmd(ClientData clientData, Tcl_Interp *interp, int argc, char *argv[])
 {
 	PythonCmd_ClientData *data = (PythonCmd_ClientData *)clientData;
-	PyObject *self, *func, *arg, *res;
+	PyObject *func, *arg, *res;
 	int i, rv;
 	Tcl_Obj *obj_res;
 
@@ -2058,7 +2058,6 @@ PythonCmd(ClientData clientData, Tcl_Interp *interp, int argc, char *argv[])
 	/* TBD: no error checking here since we know, via the
 	 * Tkapp_CreateCommand() that the client data is a two-tuple
 	 */
-	self = data->self;
 	func = data->func;
 
 	/* Create argument list (argv1, ..., argvN) */