external/test/test.sh: fix VERSION substitution when no tags
external/test/test.sh: fix VERSION substitution when no tags

i.e. we get a hash rather than a version number

This seems to be occuring in Travis if it doesn't pull a tag.

Fixes: 41f51c834a1be508ca2e7446fe8fa6abc3af473c
Signed-off-by: Stewart Smith <ec31ab75ddf977353c8f660f92ea8b23f64aef25@linux.vnet.ibm.com>

qemu/skiboot,shenki/skiboot,qemu/skiboot,stewart-ibm/skiboot,stewart-ibm/skiboot,legoater/skiboot,open-power/skiboot,legoater/skiboot,shenki/skiboot,stewart-ibm/skiboot,open-power/skiboot,shenki/skiboot,legoater/skiboot,open-power/skiboot,qemu/skiboot,shenki/skiboot,legoater/skiboot,legoater/skiboot,open-power/skiboot,shenki/skiboot,qemu/skiboot,open-power/skiboot,qemu/skiboot