loop: remove redundant initialization of pointer node

The pointer node is being initialized with a value that is never
read, it is being re-assigned the same value a little futher on.
Remove the redundant initialization. Cleans up clang scan warning:

drivers/block/loop.c:823:19: warning: Value stored to 'node' during
its initialization is never read [deadcode.DeadStores]
Signed-off-by: Colin Ian King <colin.i.king@gmail.com>
Link: https://lore.kernel.org/r/20220113001432.1331871-1-colin.i.king@gmail.comSigned-off-by: Jens Axboe <axboe@kernel.dk>

drivers/block/loop.c

@@ -820,7 +820,7 @@ static inline int queue_on_root_worker(struct cgroup_subsys_state *css)
 
 static void loop_queue_work(struct loop_device *lo, struct loop_cmd *cmd)
 {
-	struct rb_node **node = &(lo->worker_tree.rb_node), *parent = NULL;
+	struct rb_node **node, *parent = NULL;
 	struct loop_worker *cur_worker, *worker = NULL;
 	struct work_struct *work;
 	struct list_head *cmd_list;