i2c: mux: pca954x: Return error if irq_create_mapping fails

irq_create_mapping can return an error, report error to log and return.
Cleanup will occur in the probe function when an error is returned.
Suggested-by: Peter Rosin <peda@axentia.se>
Acked-by: Peter Rosin <peda@axentia.se>
Signed-off-by: Phil Reid <preid@electromag.com.au>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>

drivers/i2c/muxes/i2c-mux-pca954x.c

@@ -277,6 +277,10 @@ static int pca954x_irq_setup(struct i2c_mux_core *muxc)
 
 	for (c = 0; c < data->chip->nchans; c++) {
 		irq = irq_create_mapping(data->irq, c);
+		if (!irq) {
+			dev_err(&client->dev, "failed irq create map\n");
+			return -EINVAL;
+		}
 		irq_set_chip_data(irq, data);
 		irq_set_chip_and_handler(irq, &pca954x_irq_chip,
 			handle_simple_irq);