net/mlx5e: Remove unlikely() from WARN*() condition

"unlikely(WARN_ON_ONCE(x))" is excessive. WARN_ON_ONCE() already uses
unlikely() internally.

Signed-off-by: Denis Efremov <efremov@linux.com>
Cc: Boris Pismenny <borisp@mellanox.com>
Cc: Saeed Mahameed <saeedm@mellanox.com>
Cc: Leon Romanovsky <leon@kernel.org>
Cc: Joe Perches <joe@perches.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: netdev@vger.kernel.org
Acked-by: Saeed Mahameed <saeedm@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>