savecore: fix memory leaks

[asomers]

Summary

savecore: fix memory leaks

Most of these memory leaks are long-standing, but r362790 added a few more.
Valgrind is unable to detect them due to Capsicum. I don't know why Coverity
never spotted them.

[cem]

All memory is freed at program exit.

I don't think the additional complexity buys us anything for small programs like this.

[markj]

In D25515#563786, @cem wrote:

All memory is freed at program exit.

I don't think the additional complexity buys us anything for small programs like this.

I tend to agree. I would be more supportive if the change involved refactoring DoFile() a bit, since that function is quite sprawling.

sbin/savecore/savecore.c

987

You could avoid using a triple pointer by returning devs and making argc an output parameter, or by allocating devs in the caller.

[asomers]

Abandoning diff, since it was reviewed negatively.