Fix errors/warnings caused by vmapi headers in linux driver build.

Change-Id: Ie6207422bc9cdfa95bccb0dd38e3339142bc2cfa
diff --git a/inc/vmapi/hf/abi.h b/inc/vmapi/hf/abi.h
index 9866059..7382547 100644
--- a/inc/vmapi/hf/abi.h
+++ b/inc/vmapi/hf/abi.h
@@ -75,9 +75,9 @@
  */
 static inline struct hf_vcpu_run_return hf_vcpu_run_return_decode(uint64_t res)
 {
-	struct hf_vcpu_run_return ret;
-
-	ret.code = (enum hf_vcpu_run_code)(res & 0xff);
+	struct hf_vcpu_run_return ret = {
+		.code = (enum hf_vcpu_run_code)(res & 0xff),
+	};
 
 	/* Some codes include more data. */
 	switch (ret.code) {