stage0/app: do not try to read TreeStoreID when not using overlayfs
stage0/app: do not try to read TreeStoreID when not using overlayfs

lucasallan/rkt,cab105/rkt,lucasallan/rkt,coreos/rkt,kinvolk/rkt,jonboulle/rkt,dgonyeo/rkt,intelsdi-x/rkt,sstabellini/rkt,kinvolk/rkt,dgonyeo/rkt,alban/rkt,jakon89/rkt,dgonyeo/rkt,ybubnov/rkt,lucasallan/rkt,jonboulle/rkt,joshix/rkt,alban/rkt,alban/rkt,coreos/rkt,joshix/rkt,rkt/rkt,shobhit85/rkt,coreos/rkt,jakon89/rkt,achanda/rkt,joshix/rkt,ybubnov/rkt,rkt/rkt,intelsdi-x/rkt,joshix/rkt,jakon89/rkt,sstabellini/rkt,shobhit85/rkt,shobhit85/rkt,kinvolk/rkt,ybubnov/rkt,Shashwatsh/rkt,kinvolk/rkt,Shashwatsh/rkt,Shashwatsh/rkt,intelsdi-x/rkt,cab105/rkt,achanda/rkt,lucasallan/rkt,rkt/rkt,jonboulle/rkt,rkt/rkt,sstabellini/rkt,cab105/rkt,achanda/rkt