rtos : current_threadid move to rtos context

Change-Id: I49d9d6d64c418be601d8723cb3eea9c3716ecb6b
Signed-off-by: Michel JAOUEN <michel.jaouen@stericsson.com>
Reviewed-on: http://openocd.zylin.com/343
Tested-by: jenkins
Reviewed-by: Evan Hunter <evan@ozhiker.com>
Reviewed-by: Øyvind Harboe <oyvindharboe@gmail.com>

src/rtos/rtos.h

@@ -57,7 +57,8 @@ struct rtos
 
 	symbol_table_elem_t * symbols;
 	struct target *target;
-
+	/*  add a context variable instead of global variable */
+	int64_t current_threadid;
 	threadid_t current_thread;
 	struct thread_detail* thread_details;
 	int thread_count;