[evolution] tests: fix searchbar lookup

[Vadim Rutkovsky <vrutkovsky src gnome org>]

commit ade48aafc32c291fb80f46a67cc0fdcb7c523d5c
Author: Vadim Rutkovsky <vrutkovs redhat com>
Date:   Mon Apr 28 08:54:33 2014 -0400

    tests: fix searchbar lookup

 tests/steps/steps.py |    7 ++++---
 1 files changed, 4 insertions(+), 3 deletions(-)
---
diff --git a/tests/steps/steps.py b/tests/steps/steps.py
index 2b36709..94ce1ee 100644
--- a/tests/steps/steps.py
+++ b/tests/steps/steps.py
@@ -44,9 +44,10 @@ def view_is_opened(context, name):
 
 def get_visible_searchbar(context):
     """Wait for searchbar to become visible"""
-    searchbars = context.app.findChildren(lambda x: x.labeller.name == 'Search:' and x.showing)
-    assert wait_until(lambda x: len(x) > 0, searchbars), "No visible searchbars found"
-    return searchbars[0]
+    def get_searchbars():
+        return context.app.findChildren(lambda x: x.labeller.name == 'Search:' and x.showing)
+    assert wait_until(lambda x: len(x()) > 0, get_searchbars), "No visible searchbars found"
+    return get_searchbars()[0]
 
 
 @step(u'Open "{section_name}" section')