repair: fix undefined variable
repair: fix undefined variable

If the "trace" parameter of the repair was not given, we will use the
"trace" variable without setting it. We need to set a default value.

Signed-off-by: Nadav Har'El <625169824b719df98706d88646d0aae6f368ae4d@scylladb.com>
Message-Id: <1479136239-14204-1-git-send-email-625169824b719df98706d88646d0aae6f368ae4d@scylladb.com>

duarten/scylla,raphaelsc/scylla,raphaelsc/scylla,raphaelsc/scylla,scylladb/scylla,scylladb/scylla,scylladb/scylla,avikivity/scylla,avikivity/scylla,scylladb/scylla,avikivity/scylla,duarten/scylla,duarten/scylla