commit 67f1aee6 upstream.

The cxgb3_*_send() functions return NET_XMIT_ values, which are
positive integers values. So don't treat positive return values
as an error.
Signed-off-by: Steve Wise <swise@opengridcomputing.com>
Signed-off-by: Hariprasad Shenai <hariprasad@chelsio.com>
Signed-off-by: Doug Ledford <dledford@redhat.com>
Cc: Moritz Muehlenhoff <jmm@inutil.org>
Signed-off-by: Luis Henriques <luis.henriques@canonical.com>