Add checkpatch.pl to presubmit tests.

Change-Id: I235ea140f5f54dc8b22f1c69dcff5e99a34ff602
diff --git a/inc/vmapi/hf/abi.h b/inc/vmapi/hf/abi.h
index 2e4ec7b..6f43360 100644
--- a/inc/vmapi/hf/abi.h
+++ b/inc/vmapi/hf/abi.h
@@ -93,6 +93,7 @@
 static inline uint64_t hf_vcpu_run_return_encode(struct hf_vcpu_run_return res)
 {
 	uint64_t ret = res.code & 0xff;
+
 	switch (res.code) {
 	case HF_VCPU_RUN_WAKE_UP:
 		ret |= (uint64_t)res.wake_up.vm_id << 32;
@@ -107,6 +108,7 @@
 	default:
 		break;
 	}
+
 	return ret;
 }