kernel: core_hook: upstream ksu_umount_mnt

cherry picked from tiann@898e9d4

kernel/core_hook.c

@@ -499,14 +499,12 @@ static bool should_umount(struct path *path)
 	return false;
 }
 
-static int ksu_umount_mnt(struct path *path, int flags)
+static void ksu_umount_mnt(struct path *path, int flags)
 {
-#if LINUX_VERSION_CODE >= KERNEL_VERSION(5, 9, 0) || defined(KSU_UMOUNT)
-	return path_umount(path, flags);
-#else
-	// TODO: umount for non GKI kernel
-	return -ENOSYS;
-#endif
+	int err = path_umount(path, flags);
+	if (err) {
+		pr_info("umount %s failed: %d\n", path->dentry->d_iname, err);
+	}
 }
 
 static void try_umount(const char *mnt, bool check_mnt, int flags)
@@ -527,10 +525,7 @@ static void try_umount(const char *mnt, bool check_mnt, int flags)
 		return;
 	}
 
-	err = ksu_umount_mnt(&path, flags);
-	if (err) {
-		pr_warn("umount %s failed: %d\n", mnt, err);
-	}
+	ksu_umount_mnt(&path, flags);
 }
 
 int ksu_handle_setuid(struct cred *new, const struct cred *old)