btl/vader: fix 32-bit support

cmr=v1.7.5:ticket=#4053
bcol/basesmuma: fix initialization on 32-bit platforms

The initialization code did several allgathers on void *'s using
MPI_LONG_LONG_INT. This will produce the wrong result on 32-bit
platforms. Instead use MPI_BYTE with count = sizeof (void *).

cmr=v1.7.5:ticket=#4158