Attempting to release the RX buffer twice is an error.

Bug: 132421502
Bug: 146208457
Change-Id: I714d46db326172bf914378224edce7464d7f22d9
diff --git a/test/linux/hftest_socket.c b/test/linux/hftest_socket.c
index a07e188..b25691f 100644
--- a/test/linux/hftest_socket.c
+++ b/test/linux/hftest_socket.c
@@ -25,6 +25,7 @@
 #include "vmapi/hf/transport.h"
 
 #include "test/hftest.h"
+#include "test/vmapi/spci.h"
 
 alignas(4096) uint8_t kstack[4096];
 
@@ -68,7 +69,7 @@
 	/* Set up the mailbox. */
 	spci_rxtx_map(send_addr, recv_addr);
 
-	EXPECT_EQ(spci_rx_release().func, SPCI_SUCCESS_32);
+	EXPECT_SPCI_ERROR(spci_rx_release(), SPCI_DENIED);
 
 	/* Clean the context. */
 	ctx = hftest_get_context();
diff --git a/test/vmapi/primary_with_secondaries/mailbox.c b/test/vmapi/primary_with_secondaries/mailbox.c
index c58115a..8e2e67c 100644
--- a/test/vmapi/primary_with_secondaries/mailbox.c
+++ b/test/vmapi/primary_with_secondaries/mailbox.c
@@ -64,13 +64,13 @@
 }
 
 /**
- * Clearing an empty mailbox is a noop.
+ * Clearing an empty mailbox is an error.
  */
 TEST(mailbox, clear_empty)
 {
-	EXPECT_EQ(spci_rx_release().func, SPCI_SUCCESS_32);
-	EXPECT_EQ(spci_rx_release().func, SPCI_SUCCESS_32);
-	EXPECT_EQ(spci_rx_release().func, SPCI_SUCCESS_32);
+	EXPECT_SPCI_ERROR(spci_rx_release(), SPCI_DENIED);
+	EXPECT_SPCI_ERROR(spci_rx_release(), SPCI_DENIED);
+	EXPECT_SPCI_ERROR(spci_rx_release(), SPCI_DENIED);
 }
 
 /**
diff --git a/test/vmapi/primary_with_secondaries/memory_sharing.c b/test/vmapi/primary_with_secondaries/memory_sharing.c
index ad92087..44b5c92 100644
--- a/test/vmapi/primary_with_secondaries/memory_sharing.c
+++ b/test/vmapi/primary_with_secondaries/memory_sharing.c
@@ -832,7 +832,7 @@
 	/* Let the memory be sent from VM1 to VM2. */
 	run_res = spci_run(SERVICE_VM1, 0);
 	EXPECT_EQ(run_res.func, SPCI_MSG_SEND_32);
-	EXPECT_EQ(spci_rx_release().func, SPCI_SUCCESS_32);
+	EXPECT_EQ(spci_msg_send_receiver(run_res), SERVICE_VM2);
 
 	/* Receive memory in VM2. */
 	run_res = spci_run(SERVICE_VM2, 0);