Using new-style return values for spci_yield.

Bug: 132395846
Change-Id: I6af4343c3f84e90e1fee608988585e9eaf2ee6d4
diff --git a/inc/hf/api.h b/inc/hf/api.h
index 7dcdad3..cc45a05 100644
--- a/inc/hf/api.h
+++ b/inc/hf/api.h
@@ -57,7 +57,7 @@
 spci_return_t api_spci_msg_send(uint32_t attributes, struct vcpu *current,
 				struct vcpu **next);
 int32_t api_spci_msg_recv(bool block, struct vcpu *current, struct vcpu **next);
-int32_t api_spci_yield(struct vcpu *current, struct vcpu **next);
+void api_yield(struct vcpu *current, struct vcpu **next);
 struct spci_value api_spci_version(void);
 spci_return_t api_spci_share_memory(struct vm_locked to_locked,
 				    struct vm_locked from_locked,
diff --git a/inc/vmapi/hf/call.h b/inc/vmapi/hf/call.h
index 56bf012..b99f15b 100644
--- a/inc/vmapi/hf/call.h
+++ b/inc/vmapi/hf/call.h
@@ -89,9 +89,9 @@
  * Hints that the vcpu is willing to yield its current use of the physical CPU.
  * This call always returns SPCI_SUCCESS.
  */
-static inline int64_t spci_yield(void)
+static inline struct spci_value spci_yield(void)
 {
-	return hf_call(SPCI_YIELD_32, 0, 0, 0);
+	return spci_call((struct spci_value){.func = SPCI_YIELD_32});
 }
 
 /**