selftests/net: correct the return value for run_afpackettests

The run_afpackettests will be marked as passed regardless the return
value of those sub-tests in the script:
    --------------------
    running psock_tpacket test
    --------------------
    [FAIL]
    selftests: run_afpackettests [PASS]

Fix this by changing the return value for each tests.
Signed-off-by: NPo-Hsu Lin <po-hsu.lin@canonical.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

tools/testing/selftests/net/run_afpackettests

@@ -6,12 +6,14 @@ if [ $(id -u) != 0 ]; then
 	exit 0
 fi
 
+ret=0
 echo "--------------------"
 echo "running psock_fanout test"
 echo "--------------------"
 ./in_netns.sh ./psock_fanout
 if [ $? -ne 0 ]; then
 	echo "[FAIL]"
+	ret=1
 else
 	echo "[PASS]"
 fi
@@ -22,6 +24,7 @@ echo "--------------------"
 ./in_netns.sh ./psock_tpacket
 if [ $? -ne 0 ]; then
 	echo "[FAIL]"
+	ret=1
 else
 	echo "[PASS]"
 fi
@@ -32,6 +35,8 @@ echo "--------------------"
 ./in_netns.sh ./txring_overwrite
 if [ $? -ne 0 ]; then
 	echo "[FAIL]"
+	ret=1
 else
 	echo "[PASS]"
 fi
+exit $ret