Avoid shutdown-time crash in wpa_supplicant.

Change-Id: I1fafc5ed5a4bde2b1ac89ca7fa6bf9c3a132489e

BUG=chromium-os:8593
TEST=see if chromeos crash (from go/crash) with signature 9e97e (get_table_entry) goes away

Review URL: http://codereview.chromium.org/6813030
1 file changed