net/sfc/base: remove Falcon-specific concurrency check

net/sfc/base: remove Falcon-specific concurrency check

Falcon support has been withdrawn from libefx, however, there is still
an obsolete Falcon-specific assertion that efx_mac_stats_upload()
and efx_port_poll() aren't concurrent. To be consistent with an overall
Falcon support revocation it's desirable to remove it.

Fix debug build invalid assertion failure.

Fixes: 19b64c6ac35f ("net/sfc/base: import libefx base")
Fixes: 8c7c723dfe7c ("net/sfc/base: import MAC statistics")
Cc: stable@dpdk.org
Signed-off-by: Ivan Malov <ivan.malov@oktetlabs.ru>
Signed-off-by: Andrew Rybchenko <arybchenko@solarflare.com>
Reviewed-by: Andy Moreton <amoreton@solarflare.com>