Introducing hf_vcpu_count_t for vCPU count.

Return 0 rather than -1 on error.

Change-Id: I95cdde0744ef13e9bd748ce8ed32439d3d7f2010
diff --git a/inc/hf/api.h b/inc/hf/api.h
index 4060075..43497bf 100644
--- a/inc/hf/api.h
+++ b/inc/hf/api.h
@@ -25,7 +25,8 @@
 void api_init(struct mpool *ppool);
 spci_vm_id_t api_vm_get_id(const struct vcpu *current);
 spci_vm_count_t api_vm_get_count(void);
-int64_t api_vcpu_get_count(spci_vm_id_t vm_id, const struct vcpu *current);
+spci_vcpu_count_t api_vcpu_get_count(spci_vm_id_t vm_id,
+				     const struct vcpu *current);
 void api_regs_state_saved(struct vcpu *vcpu);
 struct hf_vcpu_run_return api_vcpu_run(spci_vm_id_t vm_id,
 				       spci_vcpu_index_t vcpu_idx,
diff --git a/inc/hf/vm.h b/inc/hf/vm.h
index bd8a905..c86da21 100644
--- a/inc/hf/vm.h
+++ b/inc/hf/vm.h
@@ -78,7 +78,7 @@
 	spci_vm_id_t id;
 	/** See api.c for the partial ordering on locks. */
 	struct spinlock lock;
-	uint32_t vcpu_count;
+	spci_vcpu_count_t vcpu_count;
 	struct vcpu vcpus[MAX_CPUS];
 	struct mm_ptable ptable;
 	struct mailbox mailbox;
@@ -97,7 +97,8 @@
 	struct vm *vm;
 };
 
-bool vm_init(uint32_t vcpu_count, struct mpool *ppool, struct vm **new_vm);
+bool vm_init(spci_vcpu_count_t vcpu_count, struct mpool *ppool,
+	     struct vm **new_vm);
 spci_vm_count_t vm_get_count(void);
 struct vm *vm_find(spci_vm_id_t id);
 struct vm_locked vm_lock(struct vm *vm);