IOSS: Fix clang warnings

(From Sierra)

Build/Test Cases Summary
Enabled Packages: SEACASIoss
Disabled Packages: Panzer,PyTrilinos,SEACASExo2mat,SEACASMat2exo
Enabled all Forward Packages
0) MPI_DEBUG => Skipped configure, build, test due to no enabled packages! => Does not affect push readiness! (-1.00 min)
1) SERIAL_RELEASE => Skipped configure, build, test due to no enabled packages! => Does not affect push readiness! (-1.00 min)
2) MPI_DEBUG_SS => passed: passed=21,notpassed=0 (22.59 min)
3) SERIAL_RELEASE_SS => passed: passed=22,notpassed=0 (24.00 min)
Copy pure-kokkos minidriver kokkos/example/fenl to trilinoscouplings/examples/fenl to begin refactoring to use Tpetra.
MueLu: FilteredAF: enable lumping by default

We want to always preserve the constant nullspace.
MueLu: FilteredAF: reuse eigenvalue from non-filtered matrix
MueLu: reenabling PgPFactory test

It still throws, but the reason is known: incorrect matrix
redistribution in Amesos (see bug #969). As it is an important bug for
us that we need to address and not ignore, I'm reenabling this test to
be a visible remindment of that.

Problem summary: during import of a matrix to a single processor, Amesos
Superlu assumes that GIDs are from 0 to the max, which may not be the
case. Some other Amesos solvers were fixed, but not SuperLU, which is
unfortunate, as that is the main working horse for us.
MueLu: CoordinatesTransferF: skip Import construction for uncoupled aggregation

It is unnecessary to fetch ghost data in this case.