Copy td_rqindex during fork instead of zero'ing it to match the comments.

I do not believe there is any functional change.

sys/sys/proc.h

@@ -263,7 +263,7 @@ struct thread {
 	int		td_ng_outbound;	/* (k) Thread entered ng from above. */
 	struct osd	td_osd;		/* (k) Object specific data. */
 	struct vm_map_entry *td_map_def_user; /* (k) Deferred entries. */
-#define	td_endzero td_base_pri
+#define	td_endzero td_rqindex
 
 /* Copied during fork1() or thread_sched_upcall(). */
 #define	td_startcopy td_endzero