COMP: SPDPDebug: various compilation errors

api      = 2412
HEAD     = da09e9203f
compiler = Gcc (system)
         = gcc (SUSE Linux) 9.3.1 20200406 [revision 6db837a5288ee3ca5ec504fbd5a765817e556ac2]
mpi      = SYSTEMOPENMPI
         = mpirun (Open MPI) 1.10.7.0.5e373bf1fd
OS       = Description:     openSUSE Leap 15.5
labels   = 64
opts     = linux64GccSPDPInt64Debug

matrices/lduMatrix/lduMatrix/lduMatrixATmul.C:94:39: error: cannot bind non-const lvalue reference of type ‘Foam::scalar& {aka float&}’ to an rvalue of type ‘Foam::scalar {aka float}’