dmaengine: idxd: Fix error handling in idxd_wq_cdev_dev_setup()

dmaengine: idxd: Fix error handling in idxd_wq_cdev_dev_setup()

We can't call kfree(dev) after calling device_register(dev).  The "dev"
pointer has to be freed using put_device().

Fixes: 42d279f9137a ("dmaengine: idxd: add char driver to expose submission portal to userland")
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Acked-by: Dave Jiang <dave.jiang@intel.com>
Link: https://lore.kernel.org/r/20200205123248.hmtog7qa2eiqaagh@kili.mountain
Signed-off-by: Vinod Koul <vkoul@kernel.org>