[evolution-data-server] Fix e_backend_factory_get_hash_key() documentation.

[Matthew Barnes <mbarnes src gnome org>]

commit 50870484b7129f8ffec7a8bf8e73a7feaa0b5aed
Author: Matthew Barnes <mbarnes redhat com>
Date:   Sat Apr 14 10:41:18 2012 -0400

    Fix e_backend_factory_get_hash_key() documentation.

 libebackend/e-backend-factory.c |    2 ++
 1 files changed, 2 insertions(+), 0 deletions(-)
---
diff --git a/libebackend/e-backend-factory.c b/libebackend/e-backend-factory.c
index 8050f38..caee05d 100644
--- a/libebackend/e-backend-factory.c
+++ b/libebackend/e-backend-factory.c
@@ -66,6 +66,8 @@ e_backend_factory_init (EBackendFactory *factory)
  * the hash key need only be unique among subclasses, not among instances of
  * each subclass.
  *
+ * Returns: a hash key which uniquely identifies @factory
+ *
  * Since: 3.4
  **/
 const gchar *