mfd: sm501: Fix leaks in probe()

[ Upstream commit 8ce24f8967df2836b4557a23e74dc4bb098249f1 ]

This code should clean up if sm501_init_dev() fails.

Fixes: b6d6454f ("[PATCH] mfd: SM501 core driver")
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Lee Jones <lee.jones@linaro.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>