iw_cxgb4: when flushing, complete all wrs in a chain

iw_cxgb4: when flushing, complete all wrs in a chain

commit d14587334580bc94d3ee11e8320e0c157f91ae8f upstream.

If a wr chain was posted and needed to be flushed, only the first
wr in the chain was completed with FLUSHED status.  The rest were
never completed.  This caused isert to hang on shutdown due to the
missing completions which left iscsi IO commands referenced, stalling
the shutdown.

Fixes: 4fe7c2962e11 ("iw_cxgb4: refactor sq/rq drain logic")
Signed-off-by: Steve Wise <swise@opengridcomputing.com>
Signed-off-by: Jason Gunthorpe <jgg@mellanox.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>