remove buffers from commit_buffer_list when commit failed.

remove buffers from commit_buffer_list when commit failed.

When pp, commit is the sync operation, cb_done() will be called at the line of
commit(). In this case, buffers will be freed in cb_done() before
LIST_FOR_EACH_ENTRY_SAFE(b, bb, &commit_buffer_list, commit_link) line done.
So commit_link should be deleted when freed.

When commit() successed, commit_link will be deleted twice. So we need to use
LIST_DELINIT instead of LIST_DEL

Change-Id: I6a09878e1eae49d31eb3f3626e005a3ae10841d8