selftests: nft_flowtable.sh: use /proc for pid checking

Some ps commands (e.g. busybox derived) have no -p option. Use /proc for
pid existence check.

Signed-off-by: Boris Sukholitko <boris.sukholitko@broadcom.com>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>

diff --git a/tools/testing/selftests/netfilter/nft_flowtable.sh b/tools/testing/selftests/netfilter/nft_flowtable.sh
index 7060bae..4d8bc51 100755 (executable)
--- a/tools/testing/selftests/netfilter/nft_flowtable.sh
+++ b/tools/testing/selftests/netfilter/nft_flowtable.sh
@@ -288,11 +288,11 @@ test_tcp_forwarding_ip()
 
        sleep 3
 
-       if ps -p $lpid > /dev/null;then
+       if test -d /proc/"$lpid"/; then
                kill $lpid
        fi
 
-       if ps -p $cpid > /dev/null;then
+       if test -d /proc/"$cpid"/; then
                kill $cpid
        fi