power: supply: ucs1002: fix error code in ucs1002_get_property()

This function is supposed to return 0 for success instead of returning
the val->intval.  This makes it the same as the other case statements
in this function.

Fixes: 81196e2e

 ("power: supply: ucs1002: fix some health status issues")
Signed-off-by: Dan Carpenter <dan.carpenter@linaro.org>
Link: https://lore.kernel.org/r/687f64a4-4c6e-4536-8204-98ad1df934e5@moroto.mountain
Signed-off-by: Sebastian Reichel <sebastian.reichel@collabora.com>