Avoid an allocation in storing and retrieving traces from contexts.
Avoid an allocation in storing and retrieving traces from contexts.

Noticed this in passing. Doubt it is important, but the change is simple
enough.

il9ue/cockroach,cuongdo/cockroach,marcuswestin/cockroach,vaibhavarora/cockroach,nieyy/cockroach,vivekmenezes/cockroach,arjun4084346/cockroach,arjun4084346/cockroach,nieyy/cockroach,il9ue/cockroach,marcuswestin/cockroach,sunya123/cockroach,arjun4084346/cockroach,petermattis/cockroach,maxlang/cockroach,nieyy/cockroach,maxlang/cockroach,paperstreet/cockroach,cockroachdb/cockroach,cuongdo/cockroach,cuongdo/cockroach,bg451/cockroach,vaibhavarora/cockroach,sunya123/cockroach,veteranlu/cockroach,il9ue/cockroach,vivekmenezes/cockroach,vaibhavarora/cockroach,arjun4084346/cockroach,cockroachdb/cockroach,arjun4084346/cockroach,cuongdo/cockroach,il9ue/cockroach,sunya123/cockroach,arjun4084346/cockroach,sunya123/cockroach,veteranlu/cockroach,bg451/cockroach,paperstreet/cockroach,veteranlu/cockroach,glycerine/cockroach,paperstreet/cockroach,paperstreet/cockroach,petermattis/cockroach,vaibhavarora/cockroach,veteranlu/cockroach,cockroachdb/cockroach,cuongdo/cockroach,petermattis/cockroach,paperstreet/cockroach,cockroachdb/cockroach,bg451/cockroach,maxlang/cockroach,veteranlu/cockroach,marcuswestin/cockroach,vaibhavarora/cockroach,marcuswestin/cockroach,nieyy/cockroach,petermattis/cockroach,sunya123/cockroach,cuongdo/cockroach,marcuswestin/cockroach,maxlang/cockroach,veteranlu/cockroach,glycerine/cockroach,maxlang/cockroach,cockroachdb/cockroach,paperstreet/cockroach,il9ue/cockroach,glycerine/cockroach,maxlang/cockroach,veteranlu/cockroach,glycerine/cockroach,petermattis/cockroach,marcuswestin/cockroach,vivekmenezes/cockroach,vivekmenezes/cockroach,bg451/cockroach,glycerine/cockroach,cockroachdb/cockroach,nieyy/cockroach,bg451/cockroach,paperstreet/cockroach,glycerine/cockroach,marcuswestin/cockroach,glycerine/cockroach,bg451/cockroach,arjun4084346/cockroach,vivekmenezes/cockroach,paperstreet/cockroach,il9ue/cockroach,vivekmenezes/cockroach,sunya123/cockroach,petermattis/cockroach,maxlang/cockroach,glycerine/cockroach,veteranlu/cockroach,bg451/cockroach,nieyy/cockroach,vaibhavarora/cockroach,petermattis/cockroach,vivekmenezes/cockroach,vivekmenezes/cockroach,marcuswestin/cockroach,sunya123/cockroach,sunya123/cockroach,arjun4084346/cockroach,maxlang/cockroach,vaibhavarora/cockroach,vaibhavarora/cockroach,nieyy/cockroach,nieyy/cockroach,cockroachdb/cockroach,il9ue/cockroach,il9ue/cockroach,cuongdo/cockroach,petermattis/cockroach,cockroachdb/cockroach,cuongdo/cockroach