usb: typec: mux: Fix unsigned comparison with less than zero

The return from the call to fwnode_property_read_u16_array is int,
it can be a negative error code however this is being assigned to
an size_t variable 'nval', hence the check is always false.
Fix this by making 'nval' an int.

Detected by Coccinelle ("Unsigned expression compared with
zero: nval < 0")

Fixes: 96a6d031 ("usb: typec: mux: Find the muxes by also matching against the device node")
Signed-off-by: YueHaibing <yuehaibing@huawei.com>
Acked-by: Heikki Krogerus <heikki.krogerus@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/usb/typec/mux.c

@@ -126,7 +126,7 @@ static void *typec_mux_match(struct device_connection *con, int ep, void *data)
 {
 	const struct typec_altmode_desc *desc = data;
 	struct typec_mux *mux;
-	size_t nval;
+	int nval;
 	bool match;
 	u16 *val;
 	int i;