cql3: clean up unneeded limit variables
cql3: clean up unneeded limit variables

Some places extracted a `limit` variable to be captured by lambdas,
but they were not used inside them.

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