LU-15699 build: without mpi build fails

LU-15699 build: without mpi build fails

RPM build must honor the --without mpi and should ensure
that packaging does not fail.

Also where multiple mpi flavors are installed only the
desired mpi_name should be loaded / unloaded

Lustre-change: https://review.whamcloud.com/46938
Lustre-commit: b07b6cd6c9622c44f45c017862103d2093e0aba1

Test-Parameters: trivial
HPE-bug-id: LUS-8718
Signed-off-by: Shaun Tancheff <shaun.tancheff@hpe.com>
Change-Id: I2367597c715f68166275a689fe62634bf8a0607f
Reviewed-by: Alexey Lyashkov <alexey.lyashkov@hpe.com>
Reviewed-by: Petros Koutoupis <petros.koutoupis@hpe.com>
Reviewed-by: James Simmons <jsimmons@infradead.org>
Reviewed-on: https://review.whamcloud.com/47712
Tested-by: jenkins <devops@whamcloud.com>
Tested-by: Maloo <maloo@whamcloud.com>
Reviewed-by: Yang Sheng <ys@whamcloud.com>
Reviewed-by: Oleg Drokin <green@whamcloud.com>