Add audit uid to netlink credentials

Most audit control messages are sent over netlink.In order to properly
log the identity of the sender of audit control messages, we would like
to add the loginuid to the netlink_creds structure, as per the attached
patch.

Signed-off-by: Serge Hallyn <serue@us.ibm.com>
Signed-off-by: David Woodhouse <dwmw2@infradead.org>

include/linux/audit.h

@@ -184,7 +184,7 @@ extern void audit_inode(const char *name, const struct inode *inode);
 
 				/* Private API (for audit.c only) */
 extern int  audit_receive_filter(int type, int pid, int uid, int seq,
-				 void *data);
+				 void *data, uid_t loginuid);
 extern void audit_get_stamp(struct audit_context *ctx,
 			    struct timespec *t, unsigned int *serial);
 extern int  audit_set_loginuid(struct audit_context *ctx, uid_t loginuid);