fix(rss): do not consider MHU_ERR_ALREADY_INIT as error

rss_comms_init() should return with success (0) in case of an internal
MHU_ERR_ALREADY_INIT error code which is harmless (occurs when
rss_comms_init() is called multiple times in a row).

Change-Id: Ibb1fef48a60866e80d3a389128cb8eef1332ea01
Signed-off-by: David Vincze <david.vincze@arm.com>
diff --git a/drivers/arm/rss/rss_comms.c b/drivers/arm/rss/rss_comms.c
index 5e224e1..4622af9 100644
--- a/drivers/arm/rss/rss_comms.c
+++ b/drivers/arm/rss/rss_comms.c
@@ -156,14 +156,22 @@
 
 	err = mhu_init_sender(mhu_sender_base);
 	if (err != MHU_ERR_NONE) {
-		ERROR("[RSS-COMMS] Host to RSS MHU driver initialization failed: %d\n", err);
-		return -1;
+		if (err == MHU_ERR_ALREADY_INIT) {
+			INFO("[RSS-COMMS] Host to RSS MHU driver already initialized\n");
+		} else {
+			ERROR("[RSS-COMMS] Host to RSS MHU driver initialization failed: %d\n", err);
+			return -1;
+		}
 	}
 
 	err = mhu_init_receiver(mhu_receiver_base);
 	if (err != MHU_ERR_NONE) {
-		ERROR("[RSS-COMMS] RSS to Host MHU driver initialization failed: %d\n", err);
-		return -1;
+		if (err == MHU_ERR_ALREADY_INIT) {
+			INFO("[RSS-COMMS] RSS to Host MHU driver already initialized\n");
+		} else {
+			ERROR("[RSS-COMMS] RSS to Host MHU driver initialization failed: %d\n", err);
+			return -1;
+		}
 	}
 
 	return 0;