cfq-iosched: free cic_index if blkio_alloc_blkg_stats fails

commit 2984ff38ccf6cbc02a7a996a36c7d6f69f3c6146 upstream.

If we fail allocating the blkpg stats, we free cfqd and cfgq.
But we need to free the IDA cfqd->cic_index as well.

Signed-off-by: majianpeng <majianpeng@gmail.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

diff --git a/block/cfq-iosched.c b/block/cfq-iosched.c
index ae21919..aae9447 100644
--- a/block/cfq-iosched.c
+++ b/block/cfq-iosched.c
@@ -4015,6 +4015,11 @@
 
 	if (blkio_alloc_blkg_stats(&cfqg->blkg)) {
 		kfree(cfqg);
+
+		spin_lock(&cic_index_lock);
+		ida_remove(&cic_index_ida, cfqd->cic_index);
+		spin_unlock(&cic_index_lock);
+
 		kfree(cfqd);
 		return NULL;
 	}