pass: Remove use-after-free of policy->pass_table during pass_exit_resource()

pass: Remove use-after-free of policy->pass_table during pass_exit_resource()

During the pass_exit_resource(), pass_put_table() frees the
g_pass->policy->pass_table, and after that, pass_hotplug_stop() is
called and uses the pointer. Remove the use-after-free by clearing
policy->pass_table from pass_put_table() instead of
__pass_governor_exit() and checking null from pass_hot_plug_stop().

Change-Id: I00d57320dd9ed9f0bcaed406f066bdce37215656
Signed-off-by: Seung-Woo Kim <sw0312.kim@samsung.com>