dpctl.at: tap devices don't exist on Windows.

The tests fail on Windows because tap device is not
a valid device on Windows. Use "dummy" device instead.

Signed-off-by: Gurucharan Shetty <gshetty@nicira.com>
Acked-by: Ben Pfaff <blp@nicira.com>

tests/dpctl.at

@@ -25,27 +25,27 @@ dummy@br0:
 	flows: 0
 	port 0: br0 (internal)
 ])
-AT_CHECK([ovs-appctl dpctl/add-if dummy@br0 vif1.0,type=tap,port_no=5])
+AT_CHECK([ovs-appctl dpctl/add-if dummy@br0 vif1.0,type=dummy,port_no=5])
 AT_CHECK([ovs-appctl dpctl/show dummy@br0], [0], [dnl
 dummy@br0:
 	lookups: hit:0 missed:0 lost:0
 	flows: 0
 	port 0: br0 (internal)
-	port 5: vif1.0 (tap)
+	port 5: vif1.0 (dummy)
 ])
-AT_CHECK([ovs-appctl dpctl/add-if dummy@br0 vif1.0,type=tap], [2], [],
+AT_CHECK([ovs-appctl dpctl/add-if dummy@br0 vif1.0,type=dummy], [2], [],
   [stderr])
 AT_CHECK([sed 's/(.*)/(...)/' stderr], [0],
   [ovs-vswitchd: adding vif1.0 to dummy@br0 failed (...)
 ovs-appctl: ovs-vswitchd: server returned an error
 ])
 AT_CHECK([ovs-appctl dpctl/set-if dummy@br0 vif1.0,port_no=5])
 AT_CHECK([ovs-appctl dpctl/set-if dummy@br0 vif1.0,type=system], [2], [],
-  [ovs-vswitchd: vif1.0: can't change type from tap to system
+  [ovs-vswitchd: vif1.0: can't change type from dummy to system
 ovs-appctl: ovs-vswitchd: server returned an error
 ])
-AT_CHECK([ovs-appctl dpctl/set-if dummy@br0 br0,type=tap], [2], [],
-  [ovs-vswitchd: br0: can't change type from internal to tap
+AT_CHECK([ovs-appctl dpctl/set-if dummy@br0 br0,type=dummy], [2], [],
+  [ovs-vswitchd: br0: can't change type from internal to dummy
 ovs-appctl: ovs-vswitchd: server returned an error
 ])
 AT_CHECK([ovs-appctl dpctl/del-if dummy@br0 vif1.0])