Changes

erab_fsm: handle RELEASE.{cmd,ind} in state erab_wait_setup_rsp

It can happen that either the eNB or the MME orders E-RAB release
(directly or indirectly via UE CONTEXT RELEASE) *before* the E-RAB
is fully setup (i.e. the erab_fsm state =/= erab_setup).

Change-Id: I91a010f304456c1593ef257051a912f0fe8ae2a1
Related: SYS#7318, SYS#7310