net/sfc: fix errno if flow API RSS action parse fails
net/sfc: fix errno if flow API RSS action parse fails

The value of rte_errno must be positive in case of an error.

Fixes: d77d07391d4d ("net/sfc: support flow API RSS action")
Cc: stable@dpdk.org

Signed-off-by: Roman Zhukov <f16c29821e9886ff1c0e57b41295b1ab035dcbd7@oktetlabs.ru>
Signed-off-by: Andrew Rybchenko <ac94ab2a8fe9a9a087f6e24dcbc16626b52c07e8@solarflare.com>

john-mcnamara-intel/dpdk,john-mcnamara-intel/dpdk,john-mcnamara-intel/dpdk,john-mcnamara-intel/dpdk