kill: use --queue option argument as sigval integer value

kill: use --queue option argument as sigval integer value

The sigqueue(3) takes two values, signal and sigval.  Contents of the
signal can be altered with --signal option argument, so the --queue
argument should be reserved to affect sigval_int.

This is regression fix introduced by commit
9e8dffd5cd29f03029b1ac99eecb129532ca5c0f.

Reference: http://man7.org/linux/man-pages/man3/sigqueue.3.html
Reported-by: Benno Schulenberg <bensberg@justemail.net>
Signed-off-by: Sami Kerola <kerolasa@iki.fi>