i2c: mux: Use __i2c_transfer() instead of calling parent's master_xfer()

Newly introduced quirks infrastructure doesn't work for the devices behind
MUXes because MUX's master_xfer() calls parent's master_xfer() directly
without checking the quirks. Instead of duplicating check code in MUX just
call __i2c_transfer() instead. This has a side effect on tracing (messages
will appear on both MUX bus and parent bus), but maybe that's not bad at
the end.
Signed-off-by: Alexander Sverdlin <alexander.sverdlin@nokia.com>
Tested-by: Łukasz Gemborowski <lukasz.gemborowski@nokia.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
Cc: stable@kernel.org
Fixes: b7f62584 ("i2c: add quirk checks to core")

drivers/i2c/i2c-mux.c

@@ -51,7 +51,7 @@ static int i2c_mux_master_xfer(struct i2c_adapter *adap,
 
 	ret = priv->select(parent, priv->mux_priv, priv->chan_id);
 	if (ret >= 0)
-		ret = parent->algo->master_xfer(parent, msgs, num);
+		ret = __i2c_transfer(parent, msgs, num);
 	if (priv->deselect)
 		priv->deselect(parent, priv->mux_priv, priv->chan_id);