The commit 1b80f00f56 made git describe
failure as fatal. But a failure can happens when no tag is in a
repository. And such a repository might exist for a internal build
system or some test environments.
Zephyr's build system is capable building without a commit hash.
This commit makes it non-fatal again and inform users that the build
system is failed to execute "git describe" but continues building with
KERNEL_VERSION_STRING.
Signed-off-by: Yasushi SHOJI <y-shoji@ispace-inc.com>
c0ff084f74