tests: Fix occasional failures for test 85.

The test case "85: ovn -- send gratuitous ARP for NAT rules on HA distributed router"
fails occaionally. On faster systems, chances of failure are higher.

This patch fixes this.

Tested-by: Flavio Fernandes <flavio@flaviof.com>
Signed-off-by: Numan Siddique <numans@ovn.org>

tests/ovn.at

@@ -11094,6 +11094,12 @@ only_broadcast_from_lrp1() {
 garp="fffffffffffff0000000000108060001080006040001f00000000001c0a80064000000000000c0a80064"
 echo $garp > expout
 
+OVS_WAIT_UNTIL(
+    [$PYTHON "$ovs_srcdir/utilities/ovs-pcap.in" hv1/snoopvif-tx.pcap > rcv_text
+     exp_rcvd=$(cat rcv_text | grep $garp | wc -l)
+     echo "expected received = $exp_rcvd"
+     test $exp_rcvd -ge 1])
+
 $PYTHON "$ovs_srcdir/utilities/ovs-pcap.in" hv1/snoopvif-tx.pcap | trim_zeros | only_broadcast_from_lrp1 | uniq > hv1_snoop_tx
 echo "packets on hv1-snoopvif:"
 cat hv1_snoop_tx
@@ -11122,12 +11128,17 @@ as hv1 reset_pcap_file snoopvif hv1/snoopvif
 as hv2 reset_pcap_file br-phys_n1 hv2/br-phys_n1
 as hv3 reset_pcap_file br-phys_n1 hv3/br-phys_n1
 
-# Wait for packets to be received.
-OVS_WAIT_UNTIL([test `wc -c < "hv1/snoopvif-tx.pcap"` -ge 100])
 trim_zeros() {
     sed 's/\(00\)\{1,\}$//'
 }
 
+# Wait for packets to be received.
+OVS_WAIT_UNTIL(
+    [$PYTHON "$ovs_srcdir/utilities/ovs-pcap.in" hv1/snoopvif-tx.pcap > rcv_text
+     exp_rcvd=$(cat rcv_text | grep $garp | wc -l)
+     echo "expected received = $exp_rcvd"
+     test $exp_rcvd -ge 1])
+
 $PYTHON "$ovs_srcdir/utilities/ovs-pcap.in" hv1/snoopvif-tx.pcap | trim_zeros | only_broadcast_from_lrp1 | uniq >  hv1_snoopvif_tx
 AT_CHECK([sort hv1_snoopvif_tx], [0], [expout])
 $PYTHON "$ovs_srcdir/utilities/ovs-pcap.in" hv3/br-phys_n1-tx.pcap | trim_zeros | only_broadcast_from_lrp1 | uniq > hv3_br_phys_tx
@@ -11173,6 +11184,12 @@ trim_zeros() {
 garp="fffffffffffff00000000001810007de08060001080006040001f00000000001c0a80064000000000000c0a80064"
 echo $garp > expout
 
+OVS_WAIT_UNTIL(
+    [$PYTHON "$ovs_srcdir/utilities/ovs-pcap.in" hv1/snoopvif-tx.pcap > rcv_text
+     exp_rcvd=$(cat rcv_text | grep $garp | wc -l)
+     echo "expected received = $exp_rcvd"
+     test $exp_rcvd -ge 1])
+
 $PYTHON "$ovs_srcdir/utilities/ovs-pcap.in" hv1/snoopvif-tx.pcap | trim_zeros | only_broadcast_from_lrp1 | uniq >  hv1_snoopvif_tx
 AT_CHECK([sort hv1_snoopvif_tx], [0], [expout])
 $PYTHON "$ovs_srcdir/utilities/ovs-pcap.in" hv3/br-phys_n1-tx.pcap | trim_zeros | only_broadcast_from_lrp1 | uniq > hv3_br_phys_tx