LU-19051 config: silent spurious messages while checking mpitests

LU-19051 config: silent spurious messages while checking mpitests

When detecting mpicc configuration, do not print warnings
or error messages in the middle of configure output.

Test-Parameters: trivial
Signed-off-by: Aurelien Degremont <adegremont@nvidia.com>
Change-Id: If536aa1d04f0d641a7b2a721869261c85907e084
Reviewed-on: https://review.whamcloud.com/c/fs/lustre-release/+/59403
Tested-by: jenkins <devops@whamcloud.com>
Tested-by: Maloo <maloo@whamcloud.com>
Reviewed-by: Andreas Dilger <adilger@whamcloud.com>
Reviewed-by: Shaun Tancheff <shaun.tancheff@hpe.com>
Reviewed-by: Timothy Day <timday@amazon.com>
Reviewed-by: Oleg Drokin <green@whamcloud.com>