CRED: Wrap current->cred and a few other accessors

Wrap current->cred and a few other accessors to hide their actual
implementation.

Signed-off-by: David Howells <dhowells@redhat.com>
Acked-by: James Morris <jmorris@namei.org>
Acked-by: Serge Hallyn <serue@us.ibm.com>
Signed-off-by: James Morris <jmorris@namei.org>
diff --git a/fs/smbfs/dir.c b/fs/smbfs/dir.c
index 9e9bb0d..e7ddd03 100644
--- a/fs/smbfs/dir.c
+++ b/fs/smbfs/dir.c
@@ -667,8 +667,7 @@
 
 	attr.ia_valid = ATTR_MODE | ATTR_UID | ATTR_GID;
 	attr.ia_mode = mode;
-	attr.ia_uid = current_euid();
-	attr.ia_gid = current_egid();
+	current_euid_egid(&attr.ia_uid, &attr.ia_gid);
 
 	if (!new_valid_dev(dev))
 		return -EINVAL;