sgsn: Fix access to subscr in sgsn_auth_update (Coverity)

Currently the access to subscr->sgsn_data->error_cause is not
protected against subscr == NULL like it is done in other code paths
of sgsn_auth_update.

This commit adds a conditional to avoid a NULL-dereference.

Fixes: Coverity CID 1264589

Sponsored-by: On-Waves ehf
1 file changed
tree: 96fa6e4d018cbe51e71ebf5471e2d44db871302c
  1. debian/
  2. hlrsync/
  3. linux-kernel/
  4. openbsc/
  5. wireshark/
  6. README