[patch] dm: check for kmalloc failure in dm_init_request_based_blk_mq_queue()

[Dan Carpenter]

We can just return -ENOMEM if the kzalloc() fails.

Fixes: 41b2facaf4ba ('dm: allocate blk_mq_tag_set rather than embed in 
mapped_device')
Signed-off-by: Dan Carpenter <dan.carpen...@oracle.com>

diff --git a/drivers/md/dm.c b/drivers/md/dm.c
index 6b7e80e..1a5f879 100644
--- a/drivers/md/dm.c
+++ b/drivers/md/dm.c
@@ -2736,6 +2736,8 @@ static int dm_init_request_based_blk_mq_queue(struct 
mapped_device *md,
        int err;
 
        md->tag_set = kzalloc(sizeof(struct blk_mq_tag_set), GFP_KERNEL);
+       if (!md->tag_set)
+               return -ENOMEM;
        md->tag_set->ops = &dm_mq_ops;
        md->tag_set->queue_depth = dm_get_blk_mq_queue_depth();
        md->tag_set->numa_node = NUMA_NO_NODE;