score: Fix _Thread_Initialize()

cpukit/score/include/rtems/score/thread.h

@@ -690,6 +690,9 @@ typedef struct  {
  *
  *  Uses a leading underscore in the structure name to allow forward
  *  declarations in standard header files provided by Newlib and GCC.
+ *
+ *  In case the second member changes (currently Join_queue), then the memset()
+ *  in _Thread_Initialize() must be adjusted.
  */
 struct _Thread_Control {
   /** This field is the object management structure for each thread. */

cpukit/score/src/threadinitialize.c

@@ -72,9 +72,9 @@ bool _Thread_Initialize(
 #endif
 
   memset(
-    &the_thread->current_state,
+    &the_thread->Join_queue,
     0,
-    information->Objects.size - offsetof( Thread_Control, current_state )
+    information->Objects.size - offsetof( Thread_Control, Join_queue )
   );
 
   for ( i = 0 ; i < _Thread_Control_add_on_count ; ++i ) {