repair: make sure there is one permit per repair with count res
repair: make sure there is one permit per repair with count res

Repair obtains a permit for each repair-meta instance it creates. This
permit is supposed to track all resources consumed by that repair as
well as ensure concurrency limit is respected. However when the
non-local reader path is used (shard config of master != shard config of
follower), a second permit will be obtained -- for the shard reader of
the multishard reader. This creates a situation where the repair-meta's
permit can block the shard permit, creating a deadlock situation.
This patch solves this by dropping the count resource on the
repair-meta's permit when a non-local reader path is executed -- that is
a multishard reader is created.

scylladb/scylla,scylladb/scylla,scylladb/scylla,scylladb/scylla