Also, rearrange things a bit to have a common c4iw_invalidate_mr()
function used everywhere that we need to invalidate.

Fixes: 49b53a93 ("iw_cxgb4: add fast-path for small REG_MR operations")
Signed-off-by: NSteve Wise <swise@opengridcomputing.com>
Signed-off-by: NDoug Ledford <dledford@redhat.com>