soundwire: stream: Add missing clear of alloc_slave_rt

The current path that skips allocating the slave runtime does not clear
the alloc_slave_rt flag, this is clearly incorrect. Add the missing
clear, so the runtime won't be erroneously cleaned up.

Fixes: f3016b8 ("soundwire: stream: sdw_stream_add_ functions can be called multiple times")
Reviewed-by: Pierre-Louis Bossart <pierre-louis.bossart@linux.intel.com>
Signed-off-by: Charles Keepax <ckeepax@opensource.cirrus.com>
Link: https://lore.kernel.org/r/20230602101140.2040141-1-ckeepax@opensource.cirrus.com
Signed-off-by: Vinod Koul <vkoul@kernel.org>

Author: charleskeepax

drivers/soundwire/stream.c

@@ -2021,8 +2021,10 @@ int sdw_stream_add_slave(struct sdw_slave *slave,
 
 skip_alloc_master_rt:
 	s_rt = sdw_slave_rt_find(slave, stream);
-	if (s_rt)
+	if (s_rt) {
+		alloc_slave_rt = false;
 		goto skip_alloc_slave_rt;
+	}
 
 	s_rt = sdw_slave_rt_alloc(slave, m_rt);
 	if (!s_rt) {