tests: Use cmd_execute() for ip link set up/down commands

The hwsim tests used to execute shell commands in the tests using the
subprocess python module. Use the cmd_execute() general function for
executing "ip link set up/down" commands so that this would also work on
remote setups.

Signed-off-by: Jonathan Afek <jonathanx.afek@intel.com>

tests/hwsim/test_ap_open.py

@@ -345,7 +345,7 @@ def test_ap_open_ifdown(dev, apdev):
 
     dev[0].connect("open", key_mgmt="NONE", scan_freq="2412")
     dev[1].connect("open", key_mgmt="NONE", scan_freq="2412")
-    subprocess.call(['ip', 'link', 'set', 'dev', apdev[0]['ifname'], 'down'])
+    hapd.cmd_execute(['ip', 'link', 'set', 'dev', apdev[0]['ifname'], 'down'])
     ev = hapd.wait_event(["AP-STA-DISCONNECTED"], timeout=10)
     if ev is None:
         raise Exception("Timeout on AP-STA-DISCONNECTED (1)")
@@ -358,7 +358,7 @@ def test_ap_open_ifdown(dev, apdev):
     # The following wait tests beacon loss detection in mac80211 on dev0.
     # dev1 is used to test stopping of AP side functionality on client polling.
     dev[1].request("REMOVE_NETWORK all")
-    subprocess.call(['ip', 'link', 'set', 'dev', apdev[0]['ifname'], 'up'])
+    hapd.cmd_execute(['ip', 'link', 'set', 'dev', apdev[0]['ifname'], 'up'])
     dev[0].wait_disconnected()
     dev[1].wait_disconnected()
     ev = hapd.wait_event(["INTERFACE-ENABLED"], timeout=10)

tests/hwsim/test_ap_psk.py

@@ -1888,13 +1888,13 @@ def test_ap_wpa2_psk_ifdown(dev, apdev):
     bssid = apdev[0]['bssid']
 
     dev[0].connect(ssid, psk=passphrase, scan_freq="2412")
-    subprocess.call(['ip', 'link', 'set', 'dev', apdev[0]['ifname'], 'down'])
+    hapd.cmd_execute(['ip', 'link', 'set', 'dev', apdev[0]['ifname'], 'down'])
     ev = hapd.wait_event(["INTERFACE-DISABLED"], timeout=10)
     if ev is None:
         raise Exception("No INTERFACE-DISABLED event")
     # this wait tests beacon loss detection in mac80211
     dev[0].wait_disconnected()
-    subprocess.call(['ip', 'link', 'set', 'dev', apdev[0]['ifname'], 'up'])
+    hapd.cmd_execute(['ip', 'link', 'set', 'dev', apdev[0]['ifname'], 'up'])
     ev = hapd.wait_event(["INTERFACE-ENABLED"], timeout=10)
     if ev is None:
         raise Exception("No INTERFACE-ENABLED event")