selftests: tc-testing: reduce rshift value

[ Upstream commit e95274dfe86490ec2a5633035c24b2de6722841f ]

After previous change rshift >= 32 is no longer allowed.
Modify the test to use 31, the test doesn't seem to send
any traffic so the exact value shouldn't matter.

Reviewed-by: Eric Dumazet <edumazet@google.com>
Link: https://patch.msgid.link/20250103182458.1213486-1-kuba@kernel.org


Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>

tools/testing/selftests/tc-testing/tc-tests/filters/flow.json

@@ -78,10 +78,10 @@
         "setup": [
             "$TC qdisc add dev $DEV1 ingress"
         ],
-        "cmdUnderTest": "$TC filter add dev $DEV1 parent ffff: handle 1 prio 1 protocol ip flow map key dst rshift 0xff",
+        "cmdUnderTest": "$TC filter add dev $DEV1 parent ffff: handle 1 prio 1 protocol ip flow map key dst rshift 0x1f",
         "expExitCode": "0",
         "verifyCmd": "$TC filter get dev $DEV1 parent ffff: handle 1 protocol ip prio 1 flow",
-        "matchPattern": "filter parent ffff: protocol ip pref 1 flow chain [0-9]+ handle 0x1 map keys dst rshift 255 baseclass",
+        "matchPattern": "filter parent ffff: protocol ip pref 1 flow chain [0-9]+ handle 0x1 map keys dst rshift 31 baseclass",
         "matchCount": "1",
         "teardown": [
             "$TC qdisc del dev $DEV1 ingress"