spark git commit: [SPARK-12489][CORE][SQL][MLIB] Fix minor issues found by FindBugs

Repository: spark Updated Branches: refs/heads/branch-1.6 a9c52d495 -> fd202485a [SPARK-12489][CORE][SQL][MLIB] Fix minor issues found by FindBugs Include the following changes: 1. Close `java.sql.Statement` 2. Fix incorrect `asInstanceOf`. 3. Remove unnecessary `synchronized` and

spark git commit: [SPARK-12489][CORE][SQL][MLIB] Fix minor issues found by FindBugs

Repository: spark Updated Branches: refs/heads/master fb572c6e4 -> 710b41172 [SPARK-12489][CORE][SQL][MLIB] Fix minor issues found by FindBugs Include the following changes: 1. Close `java.sql.Statement` 2. Fix incorrect `asInstanceOf`. 3. Remove unnecessary `synchronized` and