dmaengine: ioat: remove unnesesery double complition timer modification.

removing unnecessary mod_timer from timeout handler
incase of ioat_cleanup_preamble() is true  for cleaner code

Acked-by: Dave Jiang <dave.jiang@intel.com>
Signed-off-by: Leonid Ravich <Leonid.Ravich@emc.com>
Link: https://lore.kernel.org/r/1587589761-32690-2-git-send-email-leonid.ravich@dell.com


Signed-off-by: Vinod Koul <vkoul@kernel.org>