KVM: nSVM: Capture svm->nested.ctl as vmcb12_ctrl when preparing vmcb02

KVM: nSVM: Capture svm->nested.ctl as vmcb12_ctrl when preparing vmcb02

Grab svm->nested.ctl as vmcb12_ctrl when preparing the vmcb02 controls to
make it more obvious that much of the data is coming from vmcb12 (or
rather, a snapshot of vmcb12 at the time of L1's VMRUN).

Opportunistically reorder the variable definitions to create a pretty
reverse fir tree.

No functional change intended.

Cc: Yosry Ahmed <yosry.ahmed@linux.dev>
Reviewed-by: Yosry Ahmed <yosry.ahmed@linux.dev>
Link: https://patch.msgid.link/20260218230958.2877682-9-seanjc@google.com
Signed-off-by: Sean Christopherson <seanjc@google.com>