dmaengine: idxd: match type for retries var in idxd_enqcmds()

dmaengine: idxd: match type for retries var in idxd_enqcmds()

wq->enqcmds_retries is defined as unsigned int. However, retries on the
stack is defined as int. Change retries to unsigned int to compare the same
type.

Fixes: 7930d8553575 ("dmaengine: idxd: add knob for enqcmds retries")
Suggested-by: Thiago Macieira <thiago.macieira@intel.com>
Signed-off-by: Dave Jiang <dave.jiang@intel.com>
Link: https://lore.kernel.org/r/165031747059.3658198.6035308204505664375.stgit@djiang5-desk3.ch.intel.com
Signed-off-by: Vinod Koul <vkoul@kernel.org>