platform/x86/intel: tpmi: Fix double free in tpmi_create_device()

The previous commit 6a192c0c ("platform/x86/intel/tpmi: Fix
double free reported by Smatch") incorrectly handle the deallocation of
res variable. As shown in the comment, intel_vsec_add_aux handles all
the deallocation of res and feature_vsec_dev. Therefore, kfree(res) can
still cause double free if intel_vsec_add_aux returns error.

Fix this by adjusting the error handling part in tpmi_create_device,
following the function intel_vsec_add_dev.

Fixes: 6a192c0c ("platform/x86/intel/tpmi: Fix double free reported by Smatch")
Signed-off-by: Dongliang Mu <dzm91@hust.edu.cn>
Link: https://lore.kernel.org/r/20230309040107.534716-2-dzm91@hust.edu.cnReviewed-by: Hans de Goede <hdegoede@redhat.com>
Signed-off-by: Hans de Goede <hdegoede@redhat.com>

drivers/platform/x86/intel/tpmi.c

@@ -203,7 +203,7 @@ static int tpmi_create_device(struct intel_tpmi_info *tpmi_info,
 	struct intel_vsec_device *feature_vsec_dev;
 	struct resource *res, *tmp;
 	const char *name;
-	int ret, i;
+	int i;
 
 	name = intel_tpmi_name(pfs->pfs_header.tpmi_id);
 	if (!name)
@@ -215,8 +215,8 @@ static int tpmi_create_device(struct intel_tpmi_info *tpmi_info,
 
 	feature_vsec_dev = kzalloc(sizeof(*feature_vsec_dev), GFP_KERNEL);
 	if (!feature_vsec_dev) {
-		ret = -ENOMEM;
-		goto free_res;
+		kfree(res);
+		return -ENOMEM;
 	}
 
 	snprintf(feature_id_name, sizeof(feature_id_name), "tpmi-%s", name);
@@ -242,17 +242,8 @@ static int tpmi_create_device(struct intel_tpmi_info *tpmi_info,
 	 * feature_vsec_dev memory is also freed as part of device
 	 * delete.
 	 */
-	ret = intel_vsec_add_aux(vsec_dev->pcidev, &vsec_dev->auxdev.dev,
-				 feature_vsec_dev, feature_id_name);
-	if (ret)
-		goto free_res;
-
-	return 0;
-
-free_res:
-	kfree(res);
-
-	return ret;
+	return intel_vsec_add_aux(vsec_dev->pcidev, &vsec_dev->auxdev.dev,
+				  feature_vsec_dev, feature_id_name);
 }
 
 static int tpmi_create_devices(struct intel_tpmi_info *tpmi_info)