In case of error in build_tokens_sysfs(), all the memory that has been
allocated is freed at end of this function. But then free_group() is
called which performs memory deallocation again.

Also, instead of free_group() call, there should be exit_dell_smbios_smm()
and exit_dell_smbios_wmi() calls, since there is initialization, but there
is no release of resources in case of an error.

Fix these issues by replacing free_group() call with
exit_dell_smbios_wmi() and exit_dell_smbios_smm().

Found by Linux Verification Center (linuxtesting.org) with SVACE.

Fixes: 33b9ca1e ("platform/x86: dell-smbios: Add a sysfs interface for SMBIOS tokens")
Signed-off-by: Aleksandr Mishin <amishin@t-argos.ru>
Link: https://lore.kernel.org/r/20240830065428.9544-1-amishin@t-argos.ruReviewed-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>
Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>