fs: dlm: allow lockspaces have zero lvblen

A dlm user may not use the DLM_LKF_VALBLK flag in the DLM API,
so a zero lvblen should be allowed as a lockspace parameter.
Signed-off-by: Alexander Aring <aahringo@redhat.com>
Signed-off-by: David Teigland <teigland@redhat.com>

fs/dlm/lockspace.c

@@ -416,7 +416,7 @@ static int new_lockspace(const char *name, const char *cluster,
 	if (namelen > DLM_LOCKSPACE_LEN || namelen == 0)
 		return -EINVAL;
 
-	if (!lvblen || (lvblen % 8))
+	if (lvblen % 8)
 		return -EINVAL;
 
 	if (!try_module_get(THIS_MODULE))