CRED: Wrap task credential accesses in the networking subsystem

Wrap access to task credentials so that they can be separated more easily from
the task_struct during the introduction of COW creds.

Change most current->(|e|s|fs)[ug]id to current_(|e|s|fs)[ug]id().

Change some task->e?[ug]id to task_e?[ug]id().  In some places it makes more
sense to use RCU directly rather than a convenient wrapper; these will be
addressed by later patches.

Signed-off-by: David Howells <dhowells@redhat.com>
Reviewed-by: James Morris <jmorris@namei.org>
Acked-by: Serge Hallyn <serue@us.ibm.com>
Cc: netdev@vger.kernel.org
Signed-off-by: James Morris <jmorris@namei.org>
diff --git a/include/net/scm.h b/include/net/scm.h
index 06df126..f160116 100644
--- a/include/net/scm.h
+++ b/include/net/scm.h
@@ -54,8 +54,8 @@
 			       struct scm_cookie *scm)
 {
 	struct task_struct *p = current;
-	scm->creds.uid = p->uid;
-	scm->creds.gid = p->gid;
+	scm->creds.uid = current_uid();
+	scm->creds.gid = current_gid();
 	scm->creds.pid = task_tgid_vnr(p);
 	scm->fp = NULL;
 	scm->seq = 0;