elfcopy: stop leaving temporary files on error

[crees]

Summary

Temporary files were not cleaned up, resulting in $TMPDIR or even
the current directory becoming littered with ecp.* files.

This happened with error and even sometimes on success!

Test Plan

make buildworld

[crees]

Hold for a bit- it errs on the verbose side, so in the test suite we get unnecessary stderr output. Will add extra checks.

[crees]

elftoolchain: stop leaving tempfiles on error

Temporary files were not cleaned up, resulting in $TMPDIR or even
the current directory becoming littered with ecp.* files.

This happened with error and even sometimes on success!

Obtained from: https://sourceforge.net/p/elftoolchain/code/3918/

[crees]

I think this should be ready to go- upstream has accepted it. Are you happy with it?

[dim]

Ah sorry, totally forgotten about this. It seems to be fine, let's get it in then.

[michaelo]

Is there a reason why this has not been back ported to stable/12? Here are two issues suffering from the lack:

• https://bugs.freebsd.org/bugzilla/show_bug.cgi?id=259571
• https://bugs.freebsd.org/bugzilla/show_bug.cgi?id=255626