gprs_sgsn: In case of a Activate PDP Context timeout we should free pdp

In case of a failure this method didn't set the pctx->lib back to
NULL. In case of a timeout the callback will be made with pdp=NULL
and this would lead to leaking the PDP context. Check for the case
of having a pctx->lib != pdp and free it.

This resolves:
<000f> gprs_sgsn.c:259 freeing PDP context that still has a libgtp handle attached to it, this shouldn't happen!
1 file changed
tree: 7df6a9ab8e3350aee39a0f027d5be834c834d1fa
  1. debian/
  2. hlrsync/
  3. linux-kernel/
  4. openbsc/
  5. wireshark/
  6. README