Update intercept to match new put function

The do_put function was changed between 1.4.11 and 1.4.12 as part of the
fix to prevent a type of sibling explosion when vnodes forward requests
during handoff.  The intercept used by this test needed to be updated to
match the return type.
Merge pull request #704 from basho/bugfix/pr-pw-put-intercept

Update intercept to match new put function