msm: driver: Camerav2: Correct return logic in subdev init

The code was always returing 0 irrespective of whether the
probe is successful or not. Correct it to return the rc
value which will return the proper return value in case of
probe success or failure.

Change-Id: I43cbb89d19875ccc16c6df9e1d5d6924b2e175d9
Signed-off-by: Mayank Parashar <mayankp@codeaurora.org>