Eliminate vm_set_current.

It is a potential source of bugs if we forget to call it, and is
leftover from when hafnium had a scheduler.

Change-Id: I1ce07302ea4c40578fde43a4277b628abf3e4918
diff --git a/src/cpu.c b/src/cpu.c
index 9c7484b..4c6a18b 100644
--- a/src/cpu.c
+++ b/src/cpu.c
@@ -92,9 +92,10 @@
 	sl_unlock(&c->lock);
 
 	if (!prev) {
-		struct vcpu *vcpu =
-			&vm_get(HF_PRIMARY_VM_ID)->vcpus[cpu_index(c)];
-		arch_regs_init(&vcpu->regs, entry, arg);
+		struct vm *vm = vm_get(HF_PRIMARY_VM_ID);
+		struct vcpu *vcpu = &vm->vcpus[cpu_index(c)];
+		arch_regs_init(&vcpu->regs, true, vm->id, vm->ptable.table,
+			       entry, arg);
 		vcpu_on(vcpu);
 	}