bsc/msc: Extension can never be NULL use strlen instead

Fixes: Coverity CID 1040717
2 files changed
tree: 178ddc1d8c1ea636402f882f8d1693f8144b3a0c
  1. debian/
  2. hlrsync/
  3. linux-kernel/
  4. openbsc/
  5. wireshark/
  6. README