i40iw: Send last streaming mode message for loopback connections

i40iw: Send last streaming mode message for loopback connections

commit 07c72d7d54d138eb2ca37709a5a3d55fbcc01536 upstream.

Send a zero length last streaming mode message for loopback
connections to synchronize between accepting QP and connecting QP.
This avoids data transfer to start on the accepting QP before
the connecting QP is in RTS. Also remove function i40iw_loopback_nop()
as it is no longer used.

Fixes: f27b4746f378 ("i40iw: add connection management code")
Signed-off-by: Tatyana Nikolova <tatyana.e.nikolova@intel.com>
Signed-off-by: Shiraz Saleem <shiraz.saleem@intel.com>
Signed-off-by: Doug Ledford <dledford@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>