make sure lcls is mindspore tensor, to fix issue340 #345
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这个PR是为了解决 #340 这个issue。目前发现,该issue在所有的分支V0.3.0 V0.4.0 master都存在。该解决方案在V0.2.0分支上面做了调试,已通过。请检查是否在其他分支也能够正常使用。