commit 159ce52a upstream.

During probe the driver allocates dummy I2C device for companion chip
with i2c_new_dummy() but it does not check the return value of this call.

In case of error (i2c_new_device(): memory allocation failure or I2C
address cannot be used) this function returns NULL which is later used
by regmap_init_i2c().

If i2c_new_dummy() fails for companion device, fail also the probe for
main MFD driver.
Signed-off-by: Krzysztof Kozlowski <k.kozlowski@samsung.com>
Signed-off-by: Lee Jones <lee.jones@linaro.org>
Signed-off-by: Jiri Slaby <jslaby@suse.cz>