tty: serial: owl: Fix the link time qualifier of 'owl_uart_exit()'

tty: serial: owl: Fix the link time qualifier of 'owl_uart_exit()'

[ Upstream commit 6264dab6efd6069f0387efb078a9960b5642377b ]

'exit' functions should be marked as __exit, not __init.

Fixes: fc60a8b675bd ("tty: serial: owl: Implement console driver")
Signed-off-by: Christophe JAILLET <christophe.jaillet@wanadoo.fr>
Link: https://lore.kernel.org/r/20190910041129.6978-1-christophe.jaillet@wanadoo.fr
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>