mcelog, remove socket file on SIGINT

When running mcelog from the command line and killing it with
SIGINT, the /var/run/mcelog-client socket file is orphaned.

[root@thetango mcelog]# mcelog --daemon --foreground
mcelog: failed to prefill DIMM database from DMI data
^C
[root@thetango mcelog]# ls -l /var/run/mcelog-client
srwxr-xr-x. 1 root root 0 Aug 14 16:19 /var/run/mcelog-client

This patch introduces client_cleanup() which will cleanup the socket file
on SIGINT.

Signed-off-by: Prarit Bhargava <prarit@redhat.com>
Signed-off-by: Andi Kleen <ak@linux.intel.com>
3 files changed