Clean up after SIGHUP

Cleanly terminate and clean up after ourselves when we receive
SIGHUP, e.g. when our terminal goes away.

Signed-off-by: Stefan Reinauer <[email protected]>
Change-Id: I3788a78dd68836e96d91f6c3dccefd4d070aeb05
Reviewed-on: https://review.coreboot.org/c/em100/+/51346
Reviewed-by: ron minnich <[email protected]>
Reviewed-by: Angel Pons <[email protected]>
Tested-by: build bot (Jenkins) <[email protected]>
1 file changed