btrfs: make close_fs_devices return void

The return value of this function conveys absolutely no information.
All callers already check the state of fs_devices->opened to decide how
to proceed. So convert the function to returning void. While at it make
btrfs_close_devices also return void.
Reviewed-by: Josef Bacik <josef@toxicpanda.com>
Reviewed-by: Anand Jain <anand.jain@oracle.com>
Signed-off-by: Nikolay Borisov <nborisov@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>

fs/btrfs/volumes.c

@@ -1156,12 +1156,12 @@ static void btrfs_close_one_device(struct btrfs_device *device)
 	ASSERT(atomic_read(&device->reada_in_flight) == 0);
 }
 
-static int close_fs_devices(struct btrfs_fs_devices *fs_devices)
+static void close_fs_devices(struct btrfs_fs_devices *fs_devices)
 {
 	struct btrfs_device *device, *tmp;
 
 	if (--fs_devices->opened > 0)
-		return 0;
+		return;
 
 	mutex_lock(&fs_devices->device_list_mutex);
 	list_for_each_entry_safe(device, tmp, &fs_devices->devices, dev_list) {
@@ -1173,17 +1173,14 @@ static int close_fs_devices(struct btrfs_fs_devices *fs_devices)
 	WARN_ON(fs_devices->rw_devices);
 	fs_devices->opened = 0;
 	fs_devices->seeding = false;
-
-	return 0;
 }
 
-int btrfs_close_devices(struct btrfs_fs_devices *fs_devices)
+void btrfs_close_devices(struct btrfs_fs_devices *fs_devices)
 {
 	struct btrfs_fs_devices *seed_devices = NULL;
-	int ret;
 
 	mutex_lock(&uuid_mutex);
-	ret = close_fs_devices(fs_devices);
+	close_fs_devices(fs_devices);
 	if (!fs_devices->opened) {
 		seed_devices = fs_devices->seed;
 		fs_devices->seed = NULL;
@@ -1196,7 +1193,6 @@ int btrfs_close_devices(struct btrfs_fs_devices *fs_devices)
 		close_fs_devices(fs_devices);
 		free_fs_devices(fs_devices);
 	}
-	return ret;
 }
 
 static int open_fs_devices(struct btrfs_fs_devices *fs_devices,

fs/btrfs/volumes.h

@@ -435,7 +435,7 @@ int btrfs_open_devices(struct btrfs_fs_devices *fs_devices,
 struct btrfs_device *btrfs_scan_one_device(const char *path,
 					   fmode_t flags, void *holder);
 int btrfs_forget_devices(const char *path);
-int btrfs_close_devices(struct btrfs_fs_devices *fs_devices);
+void btrfs_close_devices(struct btrfs_fs_devices *fs_devices);
 void btrfs_free_extra_devids(struct btrfs_fs_devices *fs_devices, int step);
 void btrfs_assign_next_active_device(struct btrfs_device *device,
 				     struct btrfs_device *this_dev);