net: stmmac: selftests: Pass the IP proto mask in the TC selftest

net: stmmac: selftests: Pass the IP proto mask in the TC selftest

[ Upstream commit 9a56a27e6002e29a6707dc4238d469ec84c3a68e ]

The stmmac TC filtering rules have recently gained sanity checks to make
sure the passed keys and their respective masks are aligned with the HW
filtering abilities.

The stmmac selftests failed to pass the mask in the match data for L4
filtering tests, and are now failing consistently with -EINVAL :

$ ethtool -t eth1
[...]
23. L4 DA TCP Filtering          -22
24. L4 SA TCP Filtering          -22
25. L4 DA UDP Filtering          -22
26. L4 SA UDP Filtering          -22

Let's pass the ip_proto mask in the l4 filtering tests match data. Found
on imx8mp, which now have passing L4 tests :

$ ethtool -t eth1
[...]
23. L4 DA TCP Filtering          0
24. L4 SA TCP Filtering          0
25. L4 DA UDP Filtering          0
26. L4 SA UDP Filtering          0

While at it, initialize the masks and keys to avoid re-using whatever
was on the stack.

Fixes: 5536d7c84363 ("net: stmmac: fix l3l4 filter rejecting unsupported offload requests")
Reviewed-by: Andrew Lunn <andrew@lunn.ch>
Signed-off-by: Maxime Chevallier <maxime.chevallier@bootlin.com>
Link: https://patch.msgid.link/20260825211748.360935-1-maxime.chevallier@bootlin.com
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>