[autotest] DedupingScheduler.GetHosts() should return results

We missed a return statement in GetHosts(), meaning it would always
return None.  Whoops.

BUG=chromium-os:32459
TEST=unit
TEST=use suite_scheduler to force a new_build event on an R22 build.  it should schedule suites.
STATUS=Fixed

Change-Id: I8792c17a3a99d43d78dd6ffbb8b7307a210fdc8b
Reviewed-on: https://gerrit.chromium.org/gerrit/27093
Tested-by: Chris Masone <cmasone@chromium.org>
Reviewed-by: Scott Zawalski <scottz@chromium.org>
Commit-Ready: Chris Masone <cmasone@chromium.org>
Reviewed-by: Alex Miller <milleral@chromium.org>
diff --git a/site_utils/suite_scheduler/task.py b/site_utils/suite_scheduler/task.py
index 3935946..d790e74 100644
--- a/site_utils/suite_scheduler/task.py
+++ b/site_utils/suite_scheduler/task.py
@@ -215,7 +215,7 @@
                 or None if no hosts were found."""
         labels = [Labels.BOARD_PREFIX + board]
         if self._pool:
-          labels.append(Labels.POOL_PREFIX + self._pool)
+            labels.append(Labels.POOL_PREFIX + self._pool)
 
         return scheduler.GetHosts(multiple_labels=labels)