Fix leak of NaClAppThread structs: add missing free() call
Fix leak of NaClAppThread structs: add missing free() call

BUG=http://code.google.com/p/nativeclient/issues/detail?id=1707
TEST=look at reported leaks from run_many_threads_sequential_test
  under valgrind with --leak-check=full

Review URL: https://chromiumcodereview.appspot.com/9969084

git-svn-id: 721b910a23eff8a86f00c8fd261a7587cddf18f8@8195 fcba33aa-ac0c-11dd-b9e7-8d5594d729c2

sbc100/native_client,sbc100/native_client,sbc100/native_client,nacl-webkit/native_client,nacl-webkit/native_client,nacl-webkit/native_client,nacl-webkit/native_client,nacl-webkit/native_client,sbc100/native_client,sbc100/native_client,sbc100/native_client