IMPALA-6489: use correct template tuple size
IMPALA-6489: use correct template tuple size

The bug was that we mixed up the size of the top-level tuple with the
size of the nested tuple. The upshot in this case was that the wrong
amount of data was memcpy()ed over and we read past the bounds of the
original allocation.

Testing:
TestParquetArrayEncodings.test_avro_primitive_in_list reliably
reproduced the problem under ASAN. After the fix it not longer
reproduces.

Change-Id: I8193c04673f15e5057f457cc8a3a91a8fef64be2
Reviewed-on: http://gerrit.cloudera.org:8080/9288
Reviewed-by: Alex Behm <fe1626037acfc2dc542d2aa723a6d14f2464a20c@cloudera.com>
Reviewed-by: Dan Hecht <20ebd99959f0f6e5dcb0fc319b4d8ef53a16b5fb@cloudera.com>
Tested-by: Impala Public Jenkins

cloudera/Impala,cloudera/Impala,cloudera/Impala,cloudera/Impala,cloudera/Impala,cloudera/Impala,cloudera/Impala