Find{BLAS,LAPACK}: Revert bad refactoring of internal CHECK_*_LIBRARIES

Refactoring in commit 4c74c86f40 (FindBLAS/LAPACK: Add support for the
Fujitsu SSL2 library, 2021-01-27) was done in order to support calling
`find_library` on the dependencies as well as the candidate libraries.
However, it broke a few things:

* Intel MKL's BLAS/LAPACK are no longer found.  We specify their
  dependencies using `-l...` flags, so we should not try to use
  `find_library` for them.

* The dependencies are repeated because we accumulate them in the
  `find_library` search loop and then append them at the end too.

Revert the incorrect part of the refactoring.  Retain the flags part
needed for the Fujitsu vendor.

Fixes: #22056
2 files changed