qvm-create-default-dvm: fix permissions after creating savefile
qvm-create-default-dvm: fix permissions after creating savefile

So, savefile.img and netvm_id.txt are correctly owned as well.

woju/qubes-core-admin,QubesOS/qubes-core-admin,woju/qubes-core-admin,woju/qubes-core-admin,marmarek/qubes-core-admin,marmarek/qubes-core-admin,QubesOS/qubes-core-admin,woju/qubes-core-admin,QubesOS/qubes-core-admin,marmarek/qubes-core-admin