Use dfs.blocksize instead of deprecated dfs.block.size

The Hadoop shipped with CDH5.0.2, deprecated “dfs.block.size” (dot
between “block” and “size”) in favor of “dfs.blocksize” (no dot
between “block” and “size”)

See

  http://hadoop.apache.org/docs/r2.3.0/hadoop-project-dist/hadoop-common/DeprecatedProperties.html

Change-Id: I5eebfec4d4882afdd97ea9fb580037e7c488ba86