uio: pruss: fix missing iounmap() in pruss_probe()

platform_get_irq() is called after ioremap(), if it fails,
iounmap() needs be called in error the path.

Fixes: 2fd84b9b

 ("uio: pruss: fix to check return value of platform_get_irq() in pruss_probe()")
Signed-off-by: Yang Yingliang <yangyingliang@huawei.com>
Link: https://lore.kernel.org/r/20230808123827.560603-1-yangyingliang@huawei.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>