platform_CryptohomeLECredentialManagerServer: Add missing kwarg.

This test was failing on boards that should have been marked as N/A
because ignore_status wasn't set when checking if pinweaver_client
was present.

BUG=None
TEST=./test_that -b ${BOARD} ${TEST_HOST} \
   platform_CryptohomeLECredentialManagerServer

Change-Id: Ib9065ee2b7184533383b23ada55db285054e3485
Signed-off-by: Allen Webb <allenwebb@google.com>
Reviewed-on: https://chromium-review.googlesource.com/1287125
Reviewed-by: Andrey Pronin <apronin@chromium.org>
diff --git a/client/common_lib/cros/pinweaver_client.py b/client/common_lib/cros/pinweaver_client.py
index 6cca656..563289f 100644
--- a/client/common_lib/cros/pinweaver_client.py
+++ b/client/common_lib/cros/pinweaver_client.py
@@ -19,7 +19,7 @@
 
 def __check_pinweaver_client_present(client, message):
     cmd = 'which pinweaver_client'
-    run = client.run('which pinweaver_client')
+    run = client.run('which pinweaver_client', ignore_status=True)
     if run.exit_status != 0:  # pinweaver_client isn't present.
         raise PinWeaverNotAvailableError(run.exit_status, cmd, message);