[PATCH] bug fixes + cleanups against audit.58

Hello, This patch introduces some more bug fixes which hopefully address Rob's Oopses. I've made sure to call hlist_del_init instead of hlist_del where necessary (ie: audit_update_watch). I've also scrapped the audit_is_watched function in favor of !hlist_unhashed. One other change was putting the lock around the entire list traversal in audit_drain_watchlist, rather then in it. This was just to make the locking more uniform (ie: if auditfs_lock is held, whatever is holding it has complete control). I also rearranged auditfs_wdata_attach a bit, such that if there is no context, we return out of the function. I've also made it so the context is only made auditable if it makes it past the memory allocation. No sense in making it auditable if we were able to collect audit info. I added audit_notify_watch hooks to fs/open.c and fs/attr.c Some other little odds and ends are cleanup related. I removed the item= field from the PATH record component, I turned audit_notify_watch and auditfs_attach_wdata into void functions as we're unable to handle failed memory allocations. Reduced my goto abuse. -tim