Remove unused vcpu_off function.

Change-Id: I64546b88ecc3e65071aa644751c49354b75ebd66
diff --git a/inc/hf/cpu.h b/inc/hf/cpu.h
index e516c1b..acad7ac 100644
--- a/inc/hf/cpu.h
+++ b/inc/hf/cpu.h
@@ -125,7 +125,6 @@
 
 void vcpu_init(struct vcpu *vcpu, struct vm *vm);
 void vcpu_on(struct vcpu *vcpu, ipaddr_t entry, uintreg_t arg);
-void vcpu_off(struct vcpu *vcpu);
 size_t vcpu_index(const struct vcpu *vcpu);
 
 bool vcpu_handle_page_fault(const struct vcpu *current,
diff --git a/src/cpu.c b/src/cpu.c
index 0d3e05c..56d76a4 100644
--- a/src/cpu.c
+++ b/src/cpu.c
@@ -175,13 +175,6 @@
 	sl_unlock(&vcpu->lock);
 }
 
-void vcpu_off(struct vcpu *vcpu)
-{
-	sl_lock(&vcpu->lock);
-	vcpu->state = VCPU_STATE_OFF;
-	sl_unlock(&vcpu->lock);
-}
-
 size_t vcpu_index(const struct vcpu *vcpu)
 {
 	return vcpu - vcpu->vm->vcpus;