[autotest] Make find_possible_tests static

This doesnt need to be a class method.

BUG=chromium:672348
TEST=None

Change-Id: Ia85271a71c62d6c180847f2d4cd361c3c2e775a4
Reviewed-on: https://chromium-review.googlesource.com/448030
Commit-Ready: Allen Li <ayatane@chromium.org>
Tested-by: Allen Li <ayatane@chromium.org>
Reviewed-by: Aviv Keshet <akeshet@chromium.org>
diff --git a/server/cros/dynamic_suite/suite.py b/server/cros/dynamic_suite/suite.py
index d267148..bb50a10 100644
--- a/server/cros/dynamic_suite/suite.py
+++ b/server/cros/dynamic_suite/suite.py
@@ -1489,8 +1489,8 @@
         return tests
 
 
-    @classmethod
-    def find_possible_tests(cls, cf_getter, predicate, suite_name='', count=10):
+    @staticmethod
+    def find_possible_tests(cf_getter, predicate, suite_name='', count=10):
         """
         Function to scan through all tests and find possible tests.