soundwire: bus_type: convert open-coded while() to for() loop

No functionality change, just more structured code.
Suggested-by: Guennadi Liakhovetski <guennadi.liakhovetski@linux.intel.com>
Signed-off-by: Pierre-Louis Bossart <pierre-louis.bossart@linux.intel.com>
Reviewed-by: Rander Wang <rander.wang@linux.intel.com>
Reviewed-by: Guennadi Liakhovetski <guennadi.liakhovetski@linux.intel.com>
Signed-off-by: Bard Liao <yung-chuan.liao@linux.intel.com>
Link: https://lore.kernel.org/r/20200608205436.2402-3-yung-chuan.liao@linux.intel.comSigned-off-by: Vinod Koul <vkoul@kernel.org>

drivers/soundwire/bus_type.c

@@ -20,14 +20,12 @@
 static const struct sdw_device_id *
 sdw_get_device_id(struct sdw_slave *slave, struct sdw_driver *drv)
 {
-	const struct sdw_device_id *id = drv->id_table;
+	const struct sdw_device_id *id;
 
-	while (id && id->mfg_id) {
+	for (id = drv->id_table; id && id->mfg_id; id++)
 		if (slave->id.mfg_id == id->mfg_id &&
 		    slave->id.part_id == id->part_id)
 			return id;
-		id++;
-	}
 
 	return NULL;
 }