FAFT: Use fwtool instead of ectool for DUT using a host

On Ryu, the ectool doesn't exist. Use the fwtool instead.

BUG=chromium:527484
TEST=Ran the firmware_SoftwareSync which uses this method.

Change-Id: Ib9f88b5242ad1a2b86b7f14f426f85e8327a0d28
Reviewed-on: https://chromium-review.googlesource.com/295569
Commit-Ready: Wai-Hong Tam <waihong@chromium.org>
Tested-by: Wai-Hong Tam <waihong@chromium.org>
Reviewed-by: Shelley Chen <shchen@chromium.org>
diff --git a/client/cros/faft/rpc_functions.py b/client/cros/faft/rpc_functions.py
index 3bc3f21..48f6c2f 100755
--- a/client/cros/faft/rpc_functions.py
+++ b/client/cros/faft/rpc_functions.py
@@ -179,6 +179,10 @@
         """
         return True
 
+    def _system_has_host(self):
+        """Return True if a host is connected to DUT."""
+        return self._os_if.has_host()
+
     def _system_wait_for_client(self, timeout):
         """Wait for the client to come back online.