unbreak dtrace tracing due to double _ in rdma names

unbreak dtrace tracing due to double _ in rdma names

It looks like the dtrace trace code gets upset if you have trace names
with __ in, which the migration/rdma.c code does.

Rename the functions and the associated traces.

Fixes: 733252deb8b7d37beacda5976c2769e18642b2fa
Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
Reported-by: Andreas Färber <afaerber@suse.de>
Reviewed-by: Paolo Bonzini <pbonzini@redhat.com>
Tested-by: Andreas Färber <afaerber@suse.de>
Message-id: 1424105885-12149-1-git-send-email-dgilbert@redhat.com
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>