libceph, ceph: add __init attribution to init funcitons

Add __init attribution to the functions which are called only once
during initiating/registering operations and deleting unnecessary
symbol exports.

Signed-off-by: Chengguang Xu <cgxu519@gmx.com>
Reviewed-by: Ilya Dryomov <idryomov@gmail.com>
Signed-off-by: Ilya Dryomov <idryomov@gmail.com>
diff --git a/net/ceph/messenger.c b/net/ceph/messenger.c
index cee4b3d..fcb40c1 100644
--- a/net/ceph/messenger.c
+++ b/net/ceph/messenger.c
@@ -277,7 +277,7 @@ static void _ceph_msgr_exit(void)
 	ceph_msgr_slab_exit();
 }
 
-int ceph_msgr_init(void)
+int __init ceph_msgr_init(void)
 {
 	if (ceph_msgr_slab_init())
 		return -ENOMEM;
@@ -299,7 +299,6 @@ int ceph_msgr_init(void)
 
 	return -ENOMEM;
 }
-EXPORT_SYMBOL(ceph_msgr_init);
 
 void ceph_msgr_exit(void)
 {
@@ -307,7 +306,6 @@ void ceph_msgr_exit(void)
 
 	_ceph_msgr_exit();
 }
-EXPORT_SYMBOL(ceph_msgr_exit);
 
 void ceph_msgr_flush(void)
 {