platform/x86/amd/pmf: Fix missing error code in amd_pmf_init_smart_pc()

platform/x86/amd/pmf: Fix missing error code in amd_pmf_init_smart_pc()

On the error path, assign -ENOMEM to ret when memory allocation of
"dev->prev_data" fails.

Fixes: e70961505808 ("platform/x86/amd/pmf: Fixup error handling for amd_pmf_init_smart_pc()")
Signed-off-by: Harshit Mogalapalli <harshit.m.mogalapalli@oracle.com>
Reviewed-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>
Reviewed-by: Mario Limonciello <mario.limonciello@amd.com>
Link: https://lore.kernel.org/r/20240226144011.2100804-1-harshit.m.mogalapalli@oracle.com
Reviewed-by: Hans de Goede <hdegoede@redhat.com>
Signed-off-by: Hans de Goede <hdegoede@redhat.com>