build: Fix message indentation.
build: Fix message indentation.

Make the indentation for show-usage and show-summary consistent with
the other "show-*" targets.

Signed-off-by: James O. D. Hunt <348fbaadfbada55ea105602bf5609e23ac1c4898@intel.com>

chavafg/runtime,clearcontainers/runtime,chavafg/runtime,clearcontainers/runtime,devimc/runtime,devimc/runtime