staging: fbtft: Fix error path in fbtft_driver_module_init()

stable inclusion
from stable-v5.10.101
commit 0a7b5e8d8c1e762b0ca0ddfc74fffd584a30722c
bugzilla: https://gitee.com/openeuler/kernel/issues/I5669Z

Reference: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=0a7b5e8d8c1e762b0ca0ddfc74fffd584a30722c



--------------------------------

[ Upstream commit 426aca16 ]

If registering the platform driver fails, the function must not return
without undoing the spi driver registration first.

Fixes: c296d5f9 ("staging: fbtft: core support")
Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Link: https://lore.kernel.org/r/20220118181338.207943-1-u.kleine-koenig@pengutronix.de


Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
Signed-off-by: Yu Liao <liaoyu15@huawei.com>
Reviewed-by: Wei Li <liwei391@huawei.com>
Signed-off-by: Zheng Zengkai <zhengzengkai@huawei.com>