FS-Cache: Initialise stores_lock in netfs cookie

Initialise the stores_lock in fscache netfs cookies.  Technically, it
shouldn't be necessary, since the netfs cookie is an index and stores no
data, but initialising it anyway adds insignificant overhead.
Signed-off-by: David Howells <dhowells@redhat.com>
Reviewed-by: Jeff Layton <jlayton@redhat.com>
Acked-by: Steve Dickson <steved@redhat.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

fs/fscache/netfs.c

@@ -48,6 +48,7 @@ int __fscache_register_netfs(struct fscache_netfs *netfs)
 	cookie->flags		= 1 << FSCACHE_COOKIE_ENABLED;
 
 	spin_lock_init(&cookie->lock);
+	spin_lock_init(&cookie->stores_lock);
 	INIT_HLIST_HEAD(&cookie->backing_objects);
 
 	/* check the netfs type is not already present */