[mlir][NFC] Fix various warnings generated by GCC 9

Currently, there've been a lot of warnings while building MLIR.
This change fixes the warnings listed below.

  .../SparseTensorUtils.cpp: In instantiation of ‘...::openSparseTensorCOO(...) [with ...]’:
  .../SparseTensorUtils.cpp:1672:3:   required from here
  .../SparseTensorUtils.cpp:87:21: warning: format ‘%d’ expects argument of type ‘int’, but argument 3 has type ‘PrimaryType’ [-Wformat=]

  .../OptUtils.cpp:36:5: warning: this statement may fall through [-Wimplicit-fallthrough=]

  .../AffineOps.cpp:1741:32: warning: suggest parentheses around ‘&&’ within ‘||’ [-Wparentheses]

Reviewed By: aartbik, wrengr, aeubanks

Differential Revision: https://reviews.llvm.org/D128993