platform/x86/amd: Fix memory leak in wbrf_record()

The tmp buffer is allocated using kcalloc() but is not freed if
acpi_evaluate_dsm() fails. This causes a memory leak in the error path.

Fix this by explicitly freeing the tmp buffer in the error handling
path of acpi_evaluate_dsm().

Fixes: 58e82a62669d ("platform/x86/amd: Add support for AMD ACPI based Wifi band RFI mitigation feature")
Suggested-by: Ilpo Järvinen <[e-mail]>
Co-developed-by: Jianhao Xu <[e-mail]>
Signed-off-by: Jianhao Xu <[e-mail]>
Signed-off-by: Zilin Guan <[e-mail]>
Link: https://patch.msgid.link/[e-mail]
Reviewed-by: Ilpo Järvinen <[e-mail]>
Signed-off-by: Ilpo Järvinen <[e-mail]>

drivers/platform/x86/amd/wbrf.c

···
 	obj = acpi_evaluate_dsm(adev->handle, &wifi_acpi_dsm_guid,
 				WBRF_REVISION, WBRF_RECORD, &argv4);
 
-	if (!obj)
+	if (!obj) {
+		kfree(tmp);
 		return -EINVAL;
+	}
 
 	if (obj->type != ACPI_TYPE_INTEGER) {
 		ret = -EINVAL;