IB/rdmavt: Fix loopback send with invalidate ordering

IB/rdmavt: Fix loopback send with invalidate ordering

BugLink: https://bugs.launchpad.net/bugs/1821607
commit 38bbc9f0381550d1d227fc57afa08436e36b32fc upstream.

The IBTA spec notes:

o9-5.2.1: For any HCA which supports SEND with Invalidate, upon receiving
an IETH, the Invalidate operation must not take place until after the
normal transport header validation checks have been successfully
completed.

The rdmavt loopback code does the validation after the invalidate.

Fix by relocating the operation specific logic for all SEND variants until
after the validity checks.

Cc: <stable@vger.kernel.org> #v4.20+
Reviewed-by: Michael J. Ruhl <michael.j.ruhl@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: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Seth Forshee <seth.forshee@canonical.com>