cpufreq: governor: fix double free in cpufreq_dbs_governor_init() error path

In the Linux kernel, the following vulnerability has been resolved:

cpufreq: governor: fix double free in cpufreq_dbs_governor_init() error path

When kobject_init_and_add() fails, cpufreq_dbs_governor_init() calls

kobject_put(&dbs_data->attr_set.kobj).

The kobject release callback cpufreq_dbs_data_release() calls

gov->exit(dbs_data) and kfree(dbs_data), but the current error path

then calls gov->exit(dbs_data) and kfree(dbs_data) again, causing a

double free.

Keep the direct kfree(dbs_data) for the gov->init() failure path, but

after kobject_init_and_add() has been called, let kobject_put() handle

the cleanup through cpufreq_dbs_data_release().