Fixed memory leak as report in bug tracker (issue 13908).

Fixed minor memory leak in vtkDataReader. Also updated the
financialField test (and the data file) to add coverage
for the code in question.

Change-Id: I1cd3d0ba67bae9e4d6c56891e43b72aab65237f5
Merge topic 'fixed-leak-in-vtkDataReader' into master

f524f704 Fixed memory leak as report in bug tracker (issue 13908).