eth: mlx4: don't try to complete XDP frames in netpoll

eth: mlx4: don't try to complete XDP frames in netpoll

mlx4 doesn't support ndo_xdp_xmit / XDP_REDIRECT and wasn't
using page pool until now, so it could run XDP completions
in netpoll (NAPI budget == 0) just fine. Page pool has calling
context requirements, make sure we don't try to call it from
what is potentially HW IRQ context.

Reviewed-by: Tariq Toukan <tariqt@nvidia.com>
Link: https://patch.msgid.link/20250213010635.1354034-3-kuba@kernel.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>