api: fix coverity warning about uninitialized variable

api: fix coverity warning about uninitialized variable

CID 258269 (#1 of 1): Uninitialized scalar variable (UNINIT).
uninit_use: Using uninitialized value version.

In _cgroup_create_cgroup(), the (cg_version_t)version is uninitialized
and might be read the version in false path. It worked until now
because the version is assigned in the true path and given that its enum
the checks are not bounded by range, but rather specific.

Signed-off-by: Kamalesh Babulal <kamalesh.babulal@oracle.com>
Signed-off-by: Tom Hromatka <tom.hromatka@oracle.com>