soundwire: Initialize completion for defer messages

[ Upstream commit a306a0e4a5326269b6c78d136407f08433ab5ece ]

Deferred messages are async messages used to synchronize
transitions mostly while doing a bank switch on multi links.
On successful transitions these messages are marked complete
and thereby confirming that all the buses performed bank switch
successfully.

So, initialize the completion structure for the same.
Signed-off-by: NSanyog Kale <sanyog.r.kale@intel.com>
Signed-off-by: NShreyas NC <shreyas.nc@intel.com>
Acked-by: NPierre-Louis Bossart <pierre-louis.bossart@linux.intel.com>
Signed-off-by: NVinod Koul <vkoul@kernel.org>
Signed-off-by: NSasha Levin <sashal@kernel.org>

drivers/soundwire/bus.c

@@ -175,6 +175,7 @@ static inline int do_transfer_defer(struct sdw_bus *bus,
 
 	defer->msg = msg;
 	defer->length = msg->len;
+	init_completion(&defer->complete);
 
 	for (i = 0; i <= retry; i++) {
 		resp = bus->ops->xfer_msg_defer(bus, msg, defer);