IB/hfi1: Close VNIC sdma_progress sleep window

[ Upstream commit 18912c45 ]

The call to sdma_progress() is called outside the wait lock.

In this case, there is a race condition where sdma_progress() can return
false and the sdma_engine can idle.  If that happens, there will be no
more sdma interrupts to cause the wakeup and the vnic_sdma xmit will hang.

Fix by moving the lock to enclose the sdma_progress() call.

Also, delete the tx_retry. The need for this was removed by:
commit bcad2913 ("IB/hfi1: Serve the most starved iowait entry first")

Fixes: 64551ede ("IB/hfi1: VNIC SDMA support")
Reviewed-by: Gary Leshner <Gary.S.Leshner@intel.com>
Signed-off-by: Mike Marciniszyn <mike.marciniszyn@intel.com>
Signed-off-by: Dennis Dalessandro <dennis.dalessandro@intel.com>
Signed-off-by: Jason Gunthorpe <jgg@mellanox.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>