[PATCH v4 3/6] perf config: Use zfree() instead of free() at perf_config_set__delete()

perf_config_set__delete() delete allocated the config set but the global variable 'config_set' is used all around. So purge and zfree by an address of the global variable , i.e. 'struct perf_config_set **' type instead of using local variable 'set' of which type is 'struct perf_config_set *'.

[PATCH v4 3/6] perf config: Use zfree() instead of free() at perf_config_set__delete()

perf_config_set__delete() delete allocated the config set but the global variable 'config_set' is used all around. So purge and zfree by an address of the global variable , i.e. 'struct perf_config_set **' type instead of using local variable 'set' of which type is 'struct perf_config_set *'.