Fix @skipIfNoFBGEMM for types (#38432)
Summary:
Return unmodified type from decorator if fbgemm is present.
Fix `Tried to trace <__torch__.torch.classes.rnn.CellParamsBase object at 0x55f504c56b40> but it is not part of the active trace. Modules that are called during a trace must be registered as submodules of the thing being traced` thrown from `TestPostTrainingDynamic.test_quantized_rnn` by preserving modules in returned qRNNBase (i.e. by partially reverting https://github.com/pytorch/pytorch/pull/38134 )
Pull Request resolved: https://github.com/pytorch/pytorch/pull/38432
Differential Revision: D21567333
Pulled By: malfet
fbshipit-source-id: 364fa2c8fc6e400b4f2e425b922a977756aec1d8
