libmsc: Set trans->subscr = NULL after we release it

This is a cosmetic change and should happen to find use after free
of the subscriber.
1 file changed
tree: 160bec3e4254c9ecc81b3b155a3b329daa695aa2
  1. debian/
  2. hlrsync/
  3. linux-kernel/
  4. openbsc/
  5. wireshark/
  6. README