serial: sunsab: Fix error handling in sunsab_init()

serial: sunsab: Fix error handling in sunsab_init()

[ Upstream commit ed0ba3c5dac83dc360ebc82c610569fad8f6c3f6 ]

The sunsab_init() returns the platform_driver_register() directly without
checking its return value, if platform_driver_register() failed, the
allocated sunsab_ports is leaked.
Fix by free sunsab_ports and set it to NULL when platform_driver_register()
failed.

Fixes: ca2e7dc8004d ("[SERIAL] sunsab: Convert to of_driver framework.")
Signed-off-by: Yuan Can <yuancan@huawei.com>
Link: https://lore.kernel.org/r/20221123061212.52593-1-yuancan@huawei.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>