main: generate coredump and exit upon SIGABRT received

Previous code relied on abort() switching sigaction to SIG_FDL +
retriggering SIGABRT in case the signal handler returns, which would
then generate the coredump + terminate the process.
However, if a SIGABRT is received from somewhere else (killall -SIGABRT
osmo-bsc), then the process would print the talloc report and continue
running, which is not desired.

Change-Id: I125288283af630efa20d64505e319636964a0982
Fixes: OS#4865
1 file changed