[quant][graphmode][fx] Fix a condition check for CopyNode (#53585)
Summary:
Pull Request resolved: https://github.com/pytorch/pytorch/pull/53585
Previously fp16_static CopyNode would be marked as unquantized because of
an incorrect condition check of whether a Node is statically quantized or not.
This PR fixes that.
Test Plan: Imported from OSS
Reviewed By: vkuzo
Differential Revision: D26912677
fbshipit-source-id: 4ddb538714c5ba2db28430de5e1cf2931baf1993
