sql: fix TestLogic.
sql: fix TestLogic.

Previous commit 4ce9b6efc9f2cea52cbce5bde55c9c2e60b4c861 has
introduced sub-tests in TestLogic. However TestLogic accesses
testing.T via the logicTest wrapper struct, and this is initialized
outside of the sub-test Run call. Prior to this patch, calling
l.Fatal() on the logicTest would call t.Fatal on the outer testing.T
instance, not the one for the sub-test; this causes any
error in the sub-test to be lost upon Fatal().

This patch fixes the issue by ensuring that the logicTest wrapper
struct wraps the testing.T for the sub-test instead.

veteranlu/cockroach,maxlang/cockroach,vaibhavarora/cockroach,veteranlu/cockroach,vaibhavarora/cockroach,veteranlu/cockroach,cockroachdb/cockroach,paperstreet/cockroach,petermattis/cockroach,cockroachdb/cockroach,vaibhavarora/cockroach,glycerine/cockroach,paperstreet/cockroach,petermattis/cockroach,paperstreet/cockroach,cockroachdb/cockroach,vaibhavarora/cockroach,maxlang/cockroach,cockroachdb/cockroach,vaibhavarora/cockroach,glycerine/cockroach,cockroachdb/cockroach,petermattis/cockroach,vaibhavarora/cockroach,cockroachdb/cockroach,petermattis/cockroach,paperstreet/cockroach,paperstreet/cockroach,paperstreet/cockroach,cockroachdb/cockroach,petermattis/cockroach,cockroachdb/cockroach,glycerine/cockroach,maxlang/cockroach,paperstreet/cockroach,veteranlu/cockroach,glycerine/cockroach,glycerine/cockroach,veteranlu/cockroach,vaibhavarora/cockroach,maxlang/cockroach,maxlang/cockroach,petermattis/cockroach,paperstreet/cockroach,veteranlu/cockroach,glycerine/cockroach,maxlang/cockroach,glycerine/cockroach,petermattis/cockroach,vaibhavarora/cockroach,glycerine/cockroach,veteranlu/cockroach,veteranlu/cockroach,petermattis/cockroach,maxlang/cockroach,maxlang/cockroach