audit: Use current instead of NETLINK_CREDS() in audit_filter

Get caller process uid and gid and pid values from the current task
instead of the NETLINK_CB.  This is simpler than passing NETLINK_CREDS
from from audit_receive_msg to audit_filter_user_rules and avoid the
chance of being hit by the occassional bugs in netlink uid/gid
credential passing.  This is a safe changes because all netlink
requests are processed in the task of the sending process.

Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Eric Paris <eparis@redhat.com>
Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
diff --git a/include/linux/audit.h b/include/linux/audit.h
index 36abf2a..9c9af0e 100644
--- a/include/linux/audit.h
+++ b/include/linux/audit.h
@@ -700,7 +700,7 @@
 extern int		    audit_update_lsm_rules(void);
 
 				/* Private API (for audit.c only) */
-extern int audit_filter_user(struct netlink_skb_parms *cb);
+extern int audit_filter_user(void);
 extern int audit_filter_type(int type);
 extern int  audit_receive_filter(int type, int pid, int uid, int seq,
 				void *data, size_t datasz, uid_t loginuid,