gluster: Drop assumptions on SocketTransport names

qemu_gluster_glfs_init() passes the names of QAPI enumeration type
SocketTransport to glfs_set_volfile_server().  Works, because they
were chosen to match.  But the coupling is artificial.  Use the
appropriate literal strings instead.
Signed-off-by: NMarkus Armbruster <armbru@redhat.com>
Reviewed-by: NNiels de Vos <ndevos@redhat.com>
Signed-off-by: NKevin Wolf <kwolf@redhat.com>

block/gluster.c

@@ -412,8 +412,7 @@ static struct glfs *qemu_gluster_glfs_init(BlockdevOptionsGluster *gconf,
 
     for (server = gconf->server; server; server = server->next) {
         if (server->value->type  == GLUSTER_TRANSPORT_UNIX) {
-            ret = glfs_set_volfile_server(glfs,
-                                   GlusterTransport_lookup[server->value->type],
+            ret = glfs_set_volfile_server(glfs, "unix",
                                    server->value->u.q_unix.path, 0);
         } else {
             if (parse_uint_full(server->value->u.tcp.port, &port, 10) < 0 ||
@@ -423,8 +422,7 @@ static struct glfs *qemu_gluster_glfs_init(BlockdevOptionsGluster *gconf,
                 errno = EINVAL;
                 goto out;
             }
-            ret = glfs_set_volfile_server(glfs,
-                                   GlusterTransport_lookup[server->value->type],
+            ret = glfs_set_volfile_server(glfs, "tcp",
                                    server->value->u.tcp.host,
                                    (int)port);
         }