spi: altera: Fix memory leak on error path

Release master that have been previously allocated if the number of
chipselect is invalid.

Fixes: 8e04187c1bc7 ("spi: altera: add SPI core parameters support via platform data.")
Signed-off-by: Pan Bian <[e-mail]>
Reviewed-by: Tom Rix <[e-mail]>
Link: https://lore.kernel.org/r/[e-mail]
Signed-off-by: Mark Brown <[e-mail]>

drivers/spi/spi-altera.c

···
 			dev_err(&pdev->dev,
 				"Invalid number of chipselect: %hu\n",
 				pdata->num_chipselect);
-			return -EINVAL;
+			err = -EINVAL;
+			goto exit;
 		}
 
 		master->num_chipselect = pdata->num_chipselect;