scripts: print failed directory when testing build
scripts: print failed directory when testing build

The script test-build.sh can be used to test building several
targets with different configurations. The directory name reflects
the target and the customized configuration.
When there is a failure, it is convenient to print this build
directory to quickly know which case is failing without scrolling
the build log history.

Signed-off-by: Thomas Monjalon <ee2fa8b2681c737f775687e475dcbf2028a412f1@6wind.com>

john-mcnamara-intel/dpdk,john-mcnamara-intel/dpdk,john-mcnamara-intel/dpdk,john-mcnamara-intel/dpdk