net/funeth: Fix fun_xdp_tx() and XDP packet reclaim

The current implementation of fun_xdp_tx(), used for XPD_TX, is
incorrect in that it takes an address/length pair and later releases it
with page_frag_free(). It is OK for XDP_TX but the same code is used by
ndo_xdp_xmit. In that case it loses the XDP memory type and releases the
packet incorrectly for some of the types. Assorted breakage follows.

Change fun_xdp_tx() to take xdp_frame and rely on xdp_return_frame() in
reclaim.

Fixes: db37bc17

 ("net/funeth: add the data path")
Signed-off-by: Dimitris Michailidis <dmichail@fungible.com>
Link: https://lore.kernel.org/r/20220726215923.7887-1-dmichail@fungible.com
Signed-off-by: Paolo Abeni <pabeni@redhat.com>