msm: camera: sensor: Free vc_cfg pointer in case of error

1.Free localy allocated vc_cfg pointer to prevent memory
leak in case of failed operation copy from user.
2.Bugfix to free array of pointers.

Change-Id: I68fd7200ad7bc8298da1edb5f6556900ab153d01
Signed-off-by: Deepak Kaushal <dkaushal@codeaurora.org>
Signed-off-by: Vasko Kalanoski <vaskok@codeaurora.org>