mboxd: Cleanup errnos not captured by tests

Change-Id: I95d1eee536e4113867fceb5dcda45e15dc032002
Signed-off-by: Andrew Jeffery <andrew@aj.id.au>
diff --git a/lpc.c b/lpc.c
index 4b9d384..f64e5d1 100644
--- a/lpc.c
+++ b/lpc.c
@@ -119,7 +119,7 @@
 	/* Don't let the host access flash while we're suspended */
 	if (context->state & STATE_SUSPENDED) {
 		MSG_ERR("Can't point lpc mapping to flash while suspended\n");
-		return -MBOX_R_PARAM_ERROR;
+		return -EBUSY;
 	}
 
 	MSG_INFO("Pointing HOST LPC bus at the flash\n");
@@ -130,7 +130,7 @@
 			== -1) {
 		MSG_ERR("Failed to point the LPC BUS at the actual flash: %s\n",
 			strerror(errno));
-		return -MBOX_R_SYSTEM_ERROR;
+		return -errno;
 	}
 
 	context->state = ACTIVE_MAPS_FLASH;