Fix or remove internal error check in decompInitMod.F90 for nclumps

[ekluzek]

There's an error check in decompInitMod.F90 where the write and the endrun call contradict each other. This should be fixed or removed.

The case for removing it, is that nclumps is currently a positive integer multiplied by npes, so it can never happen normally.

However, if the code were to change or parts of the code moved around you might want it to happen to save debugging time. So fixing it and adding a unit test for it, might be the best thing to do.

The error message is now in

decompInit_lnd_check_errors

as follows...

            if (nclumps < npes) then
               ier = 1
               write(iulog,*) 'Number of gridcell clumps= ',nclumps, &
                     ' is less than the number of processes = ', npes
               call endrun(msg="Number of clumps exceeds number of processes", &
                           file=sourcefile, line=__LINE__)
               return
            end if

and the endrun message contradicts the message in the write. So it should be fixed or removed.

Originally posted by @ekluzek in #3517 (comment)