ceph: fix sparse endian warning

Use the __le macro, even though for -1 it doesn't matter.

Signed-off-by: Sage Weil <sage@newdream.net>
diff --git a/fs/ceph/super.c b/fs/ceph/super.c
index 0ae40ba..1ac7b07 100644
--- a/fs/ceph/super.c
+++ b/fs/ceph/super.c
@@ -804,7 +804,7 @@
 	struct ceph_client *client;
 	int err;
 	int (*compare_super)(struct super_block *, void *) = ceph_compare_super;
-	const char *path = 0;
+	const char *path = NULL;
 	struct ceph_mount_args *args;
 
 	dout("ceph_get_sb\n");