Fix memory leak in verifier.

We create std::ostringstream objects for failure messages but it appears we did
not delete them upon destruction. This CL fixes this.

Change-Id: If95c6f1b154db9c1d49ade4c1384ef6015663419
(cherry picked from commit 33691abbc43850fd2b2951256c4b6bbc9733ccc8)
1 file changed