block: tidy ThrottleGroupMember initializations

Move the CoMutex and CoQueue inits inside throttle_group_register_tgm()
which is called whenever a ThrottleGroupMember is initialized. There's
no need for them to be separate.

Reviewed-by: Alberto Garcia <berto@igalia.com>
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Signed-off-by: Manos Pitsidianakis <el13635@mail.ntua.gr>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>

block/block-backend.c

@@ -273,9 +273,6 @@ BlockBackend *blk_new(uint64_t perm, uint64_t shared_perm)
     blk->shared_perm = shared_perm;
     blk_set_enable_write_cache(blk, true);
 
-    qemu_co_mutex_init(&blk->public.throttle_group_member.throttled_reqs_lock);
-    qemu_co_queue_init(&blk->public.throttle_group_member.throttled_reqs[0]);
-    qemu_co_queue_init(&blk->public.throttle_group_member.throttled_reqs[1]);
     block_acct_init(&blk->stats);
 
     notifier_list_init(&blk->remove_bs_notifiers);

block/throttle-groups.c

@@ -508,6 +508,9 @@ void throttle_group_register_tgm(ThrottleGroupMember *tgm,
                          read_timer_cb,
                          write_timer_cb,
                          tgm);
+    qemu_co_mutex_init(&tgm->throttled_reqs_lock);
+    qemu_co_queue_init(&tgm->throttled_reqs[0]);
+    qemu_co_queue_init(&tgm->throttled_reqs[1]);
 
     qemu_mutex_unlock(&tg->lock);
 }