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/net/socket.c b/net/socket.c
index 57550c3..62c7729 100644
--- a/net/socket.c
+++ b/net/socket.c
@@ -491,8 +491,8 @@
 	sock = SOCKET_I(inode);
 
 	inode->i_mode = S_IFSOCK | S_IRWXUGO;
-	inode->i_uid = current->fsuid;
-	inode->i_gid = current->fsgid;
+	inode->i_uid = current_fsuid();
+	inode->i_gid = current_fsgid();
 
 	get_cpu_var(sockets_in_use)++;
 	put_cpu_var(sockets_in_use);