[quant] Fix comparison against reference for test_qat_functional_linear (#68061)
Summary:
Pull Request resolved: https://github.com/pytorch/pytorch/pull/68061
Test had a typo that didn't compare test value against reference value, fixed typo.
Test Plan:
`pytest test/quantization/fx/test_quantize_fx.py -v -k "test_qat_functional_linear"`
Imported from OSS
Reviewed By: HDCharles
Differential Revision: D32280803
fbshipit-source-id: d57a25a0dcdd88df887a39b5117abafaf15125b2
