gsm0408_test.c: Don't pass negative value to strerror()

Change-Id: I4fcf24ec1bc974a3189486d2372b9713d7fdab70
Fixes: Coverity CID 135192
1 file changed
tree: 122a4d0a8f98381f8bbcd5a1badc09bee67bfcee
  1. contrib/
  2. debian/
  3. openbsc/
  4. .gitignore
  5. .gitreview
  6. .mailmap