tests: With iptables-nft, TRACE works differently

This is 'meta nftrace' internally, therefore have to use
'xtables-monitor --trace' command to fetch the traces (which also look a
bit differently).

Related: RHEL-14147

tests/TRACE-target-of-iptables-can-t-work-in/runtest.sh

@@ -99,6 +99,22 @@ rlJournalStart
         else
             rlLogInfo "new kernel detected: skipping loading modules and associated checks"
         fi
+        if rlIsRHEL '>7' || rlIsFedora '>31' || rlIsCentOS '>7'; then
+            # assume iptables-nft
+            xtables-monitor --trace >messages.current &
+            monitor_pid=$!
+
+            ipv4_ping
+            ipv6_ping
+
+            kill $monitor_pid
+
+            rlAssertGrep "TRACE: 2 .* -4 " messages.current
+            rlAssertGrep "TRACE: 10 .* -6 " messages.current
+            echo --debug_START--
+            cat messages.current
+            echo --debug_END--
+        else
             ipv4_ping; ipv6_ping
             rlRun "get_messages > messages.current"
 
@@ -109,6 +125,7 @@ rlJournalStart
             echo --debug_START--
             cat diff.2
             echo --debug_END--
+        fi
     rlPhaseEnd
 
     rlPhaseStartCleanup