Fix OpenBLAS discovery (#53168)
Summary:
Fix accidental regression introduced by https://github.com/pytorch/pytorch/issues/47940
`FIND_PACKAGE(OpenBLAS)` does not validate that discovered library can actually be used, while `check_fortran_libraries` does that
Pull Request resolved: https://github.com/pytorch/pytorch/pull/53168
Test Plan: Build PyTorch with static OpenBLAS and check that `torch.svd(torch.ones(3, 3)).S` do not raise an exception
Reviewed By: walterddr
Differential Revision: D26772345
Pulled By: malfet
fbshipit-source-id: 3e4675c176b30dfe4f0490d7d3dfe4f9a4037134
