selftests: fib_nexthops: do not mark skipped tests as failed

The current test marks all unexpected return values as failed and sets ret
to 1. If a test is skipped, the entire test also returns 1, incorrectly
indicating failure.

To fix this, add a skipped variable and set ret to 4 if it was previously
0. Otherwise, keep ret set to 1.

Signed-off-by: Hangbin Liu <liuhangbin@gmail.com>
Link: https://patch.msgid.link/20250220085326.1512814-1-liuhangbin@gmail.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

tools/testing/selftests/net/fib_nexthops.sh

@@ -76,11 +76,13 @@ log_test()
 		printf "TEST: %-60s  [ OK ]\n" "${msg}"
 		nsuccess=$((nsuccess+1))
 	else
-		ret=1
-		nfail=$((nfail+1))
 		if [[ $rc -eq $ksft_skip ]]; then
+			[[ $ret -eq 0 ]] && ret=$ksft_skip
+			nskip=$((nskip+1))
 			printf "TEST: %-60s  [SKIP]\n" "${msg}"
 		else
+			ret=1
+			nfail=$((nfail+1))
 			printf "TEST: %-60s  [FAIL]\n" "${msg}"
 		fi
 
@@ -2528,6 +2530,7 @@ done
 if [ "$TESTS" != "none" ]; then
 	printf "\nTests passed: %3d\n" ${nsuccess}
 	printf "Tests failed: %3d\n"   ${nfail}
+	printf "Tests skipped: %2d\n"  ${nskip}
 fi
 
 exit $ret