[ Upstream commit 536cc27d ]

devm_regmap_init_i2c may fail and return NULL. The fix returns
the error when it fails.
Signed-off-by: Kangjie Lu <kjlu@umn.edu>
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>