scripts/log: do not interpret log string as printf format

Signed-off-by: "Yann E. MORIN" <yann.morin.1998@anciens.enib.fr>
(transplanted from 5f01a23be1e427f95806bbf5d880f5ee6839bed1)

# Compute Alpha-specific values

CT_DoArchTupleValues () {

    # The architecture part of the tuple:

    CT_TARGET_ARCH="${CT_ARCH}${CT_ARCH_ALPHA_VARIANT}"

}