octeontx2-pf: Do xdp_do_flush() after redirects.

xdp_do_flush() should be invoked before leaving the NAPI poll function
if XDP-redirect has been performed.

Invoke xdp_do_flush() before leaving NAPI.

Cc: Geetha sowjanya <gakula@marvell.com>
Cc: Subbaraya Sundeep <sbhatta@marvell.com>
Cc: Sunil Goutham <sgoutham@marvell.com>
Cc: hariprasad <hkelam@marvell.com>
Fixes: 06059a1a

 ("octeontx2-pf: Add XDP support to netdev PF")
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Acked-by: Geethasowjanya Akula <gakula@marvell.com>
Acked-by: Jesper Dangaard Brouer <hawk@kernel.org>
Signed-off-by: Paolo Abeni <pabeni@redhat.com>