audit: drop audit_log_abend()

The audit_log_abend() is used only by the audit_core_dumps(). Thus there is no
need of maintaining the audit_log_abend() as a separate function.

This patch drops the audit_log_abend() and pushes its functionalities back to
the audit_core_dumps(). Apart from that the "reason" field is also dropped
from being logged since the reason can be deduced from the signal number.

Signed-off-by: Paul Davies C <pauldaviesc@gmail.com>
Acked-by: Eric Paris <eparis@redhat.com>
Signed-off-by: Richard Guy Briggs <rgb@redhat.com>
Signed-off-by: Eric Paris <eparis@redhat.com>