dmaengine: idxd: off by one in cleanup code

The clean up is off by one so this will start at "i" and it should start
with "i - 1" and then it doesn't unregister the zeroeth elements in the
array.

Fixes: c52ca478

 ("dmaengine: idxd: add configuration component of driver")
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Acked-by: Dave Jiang <dave.jiang@intel.com>
Link: https://lore.kernel.org/r/X9nFeojulsNqUSnG@mwanda
Signed-off-by: Vinod Koul <vkoul@kernel.org>